That helps a bit, thanks. Your weighting description I find a little confusing and leads me to suspect that you don't have that quite dialed in yet. But I'm going to assume that you need a fair amount of weight. It also appears that you do mostly fresh water local diving with some trips to the coast. I'm guessing that your mode of transport is mostly by auto and that flying around the world ain't your bag.
First off, I think that you need to get this idea of saving money out of your head...at least in terms of your future plans. Having tech diving as a goal is fine, but I think that's all it should be for now. Focus on getting as much experience as you can in the OW realm and buy your gear with that in mind. The cost of tech diving is so HUGE that about the only thing you're gonna save by buying a BP/wing is the cost of a standard BC...you can just skip that step that a lot of us went through. In the same vein, you should realize that what you buy today is likely not what you will need in the future...again with your stated goal in mind. For instance,while you MAY be able to use the plate, you still will have to buy another wing. But really, this is a drop in the bucket compared to the costs of tech diving.
Another thing... Is this humping gear for two miles what you do now...or is this something that is associated with your future plans of 'penetrating a deep cold wreck'? I can't think of any specific BP/wing combo that is going to be easier than another with this in mind. Pads might ease the pain a little...for a few steps...maybe...but you're still gonna have a minimum of 35 pounds on your back. I think a BP is probably better than a standard BC in that the plate helps get the weight up on your shoulder and off the lower back...but still...it just isn't going to be fun hiking a long distance with all your dive gear no matter what. It sounds like you need a horse or a Tennessee sherpa...well that's what I would do if I had to hike any further than a half a mile.
As far as specific gear choices are concerned, since you stated that you aren't interested in "paying a chunk of money for a brand name", I would suggest that you look at Tobin's line or maybe even Oxycheq. Unfortunately, given your need for weight, to set up a fine tuned rig you will have to invest in a few other things that you might not need if your weight requirement was less.
It would be easy to say, "ah...just get a SS plate and a wing." But I think that overlooks your specific needs and while you could certainly do that, it would leave you with a rig that is...uh...less than optimal. Think about it...if you need 30 pounds when you hit the beach and you're in a 6 pound rig, you're gonna have to sling a 24 pound weight belt. Even in your fresh water environment you would still need 20. So much for good trim. It is very likely that you will be able to shed some of that weight requirement with some practice and education...but even so...if your main thing is cold water, you are gonna need the appropriate exposure protection and that translates to significant weight.
What additional gear am I talking about? Some combination of a heavy plate (or some variation of same) and/or a STA (standard or weighted) and/or cam band weight pockets would serve you best.
This is how I would suggest you do it...
Given what you have told us I think an inner bladder/outer shell type of wing would serve you best. With that in mind, order up a singles rig from Tobin. Get his standard 30# wing...you don't need a 40...rigged with his standard plate and hog harness. 445 bucks...you will not find a better deal for superb quality and craftsmanship and his personal support is without rival. Don't buy the other stuff, yet. But be aware that to tune your rig you will probably have to get a few more things.
After you get his rig, spend some time diving it. Read up here on SB about a "balanced rig' and study up on how to determine your true weighting requirements. Then get in the water and figure it out. After you do that, you can then start putting together what you need to get things dialed in.
As you know, Tobin's plate accepts additional weight plates. Bam! You can immediately bump your plate up to 14 pounds. Then you can add my personal favorite solution for high weight requirements...cam band weight pockets. They allow you to add up to 12 pounds on your back but better yet, they allow you to shift weight up and down the cylinder and on and off your weight belt while facilitating trim. I also always recommend getting a STA. They make things SOOO easy and they give some extra support when using cam band pockets. You can tweak things here as well by using a standard 2 to 3 pound STA or a weighted 6 pounder.
Having said all of that, let me add a qualifier. My wings are Halcyon and Agir and I use a combination of plates and STAs from Halcyon and FredT. While I have and use one of Tobin's plates, I do not have his wing. I have no doubt that his wing is of the finest quality, having heard so much about them, but I have not yet put together all of his gear in the manner described above. Even so, I can't imagine why it wouldn't work.
Lots of stuff to consider and a lot of what Ive suggested some might find over-complicated. But I'm a big believer in making use of all the advantages of a BP and wing, especially the modularity and 'tweakablity' that it affords the user. If you're gonna go down that road why not do it right.