Been using a back inflate BC (Zeagle Stiletto) and thinking about purchasing a BP/W setup.
If you move from a soft, back-inflate BCD to a SS BP/W, I think you probably won't need any added weight (i.e you can lose the weight you are currently using), with a t-shirt and shorts. I could suggest any one of a number of BPs (Dive Rite, OMS, Zeagle, etc.), but the biggest comment is, go with SS rather than aluminum, given the data you provided. You are currently using 8 lbs, with a slightly 'floaty' BCD. With a SS BP, you probably won't need any weight, or at most 2 lbs.
I fully agree with one comment from another poster on the wing - go minimalist - an 18 pound wing should be fine.
Comfort is a must since I'll often be using without protection. I'm figuring I'd want a back pad and padded straps?
I REALLY don't think you will. Neither of these items is needed, unless you plan to hike 5 miles from your car to the dive site, wearing your scuba unit on your back. Go minimalist - a simple web harness. In the water you won't notice the weight of the unit. If chaffing is any issue, wear a t-shirt.
Not sure which weight pockets, accessory pockets and other accessories to buy.
I would not buy any, to start with. Yes, you give up BCD pockets in the switch to a BP. And, with a t-shirt and shorts, you may not have any pockets. But, try a simple BP, with a one-piece harness, and no accesory pockets, first. See how it works for you, before buying other 'stuff'.
rongoodman:
I wore my Halcyon SS plate with standard one piece harness over a T-shirt on Bonaire a couple of years back without issue.
Sounds like a plan for you, as well. I usually do not recommend diving with (only) a t-shirt and board shorts in a coral reef environment, but that is just me. I like exposure suit protection from jellies, coral, etc - not because I have bouyancy issues, but because s**t happens. However, the choice is up to you.