Trekride,
The single most important thing about buying any piece of gear is how it fits YOU. What ever you end up buying please be sure you get it wet! If you can't try it on/use it I would be VERY VERY suspect of that vendor. Some of the better internet vendors will do this. Good shop owners and retailers want you to be happy with the gear you dive. In the end they know that quality gear that fits benefits you both. I own a SP wet suit and a set of gloves that rock, but I wore a few different brands before buying what I have now. It is tempting to buy stuff from friends, or internet sites, but be sure that you can first, get it serviced, second has some type of warranty, and third somebody you know has used it.
Your BCD should really be your first purchase as that piece of gear influences your dive the most after your mask. It will always affect how you position in the water, and how you manage your water presence. Its the one piece of gear that really does make a difference. I would strongly recommend you try both a jacket and a back inflate model. Both have benefits and drawbacks. Talk to your instructor staff about those. Also please don't be tempted initially by the reg portion of your gear. Take your time and try multiple brands and types. There are very minor differences in the performance of better quality regulators with SP being a good one. The one difference I found to be the most significant is how the reg fits and carries in your mouth. By that I mean how heavy is it, how well do the hoses swivel, etc. A good quality BCD will cost you about $500 and a full reg set up with a computer around $1200. Remember cheaper initially will probably cost you in the long run. You may run into some peer pressure along the way. That's probably ok if you trust the people you dive with. Just be sure that the 3 things I said earlier apply.
Best of luck, buying gear is a heck a lot of fun. The cool thing about the gear we use is if you take care of it you generally don't have to replace it like balls, and shoes. You will probably end up with a couple of different "sets" of gear depending on what you eventually find rocks your world. Just remember gear is part of the fun stuff and enjoy the process of finding your dive armor!!