I know your question has been answered, but thought I would add that the other bonus of the back inflate is that your boobs don't get squished when you fill your jacket. It can throw you slightly forward in the water at the surface, but I just lean right back and use my jacket like an armchair.
As for regs, now I have gone for Scubapro which have been great. Really top quality with a nice smooth breathe, but relatively simple in their design and make up, so less room for problems to develop. I have the MK25, which could take me into quite cold environments should I ever feel mad enough to go diving over here. I personally like the tropical stuff.
Get DIN valves too if you can, I have seen sooo many A-clamp valves leak, there again DIN may be the norm in the states anyway, I am not sure. If you plan to dive in Maine, I would definitely say go for stuff that can deal with the cold, as from what I have heard, I think it can be a bit chilly in the water there.
Good luck and keep up the diving.
