Personally I like 15ga (30-34*) over 16ga. I don't think 18ga is a good choice for anything more than decorations (molding, etc). Keeping in mind you can find 16ga in both straight and angled, it's just simpler for me to go with 15ga.
Hitachi, DeWalt & PC all use the same 15ga angled nails as the HF 34* and you can go into the store and try out, and you can get nails from both big boxes. Hitachi nails in Lowe's, PC nails in HD. I have personally used both the PC & Hitachi and they're good nailers, few misfires if any, and I own the HF (copy of the older PC) which is also just as good.
Keep in mind even though the Stanley Bostitch is 15ga, the nails are 25* instead. I also don't mess with the Paslode myself (30* i think) because it's an expensive system to get into, and more expensive than air in the long term. My dad had one and liked it, but I think he just liked having a nail gun since he likes my HF guns just as much.
What you're doing is too small to go with any kind of framing nailer, so as an additional suggestion, the HF 3 in 1 will give you a better idea of what you're going to get out of those different types.