How hard is it to attach the Transpac Harness to a Wing? I'm considering this for my first BC purchase and want to make sure I'm not getting in over my head.
As several have said, not difficult, doesn't take that long, althoug you have to pay attention as you do it. It isn't quite a 'Lego' set-up.
I've been told this is an nice set up that can "grow with my diving".
It can. It is a competent BCD for single tank diving, and can allow you to move to backmount doubles if that becomes an interest, OR sidemount doubles with the additional of a butt-plate. I have started recommending that relatively newer divers, who think they may eventually consider two tank diving, consoider the TransPac when they decide to buy their first BCD. Previously, it was all 'BP/W'.
Also, how do you decide which wing to purchase? I am considering the Rec EXP or the Voyager EXP. Any input on either of these wings?
For single tank diving, you need a relatively minimum amount of lift, and you want something designed for single tanks and therefore streamlined in that configuration. Most single tank wings fall in the 18-30lbs lift range, with a few exceptions. The REC is more lift than you need. In fact, the Voyager is probably more than you need. If you want to stay in the Dive Rite line, the Travel wing may be a better consideration. The Oxycheq Mach V is a VERY nice wing, and is available in 18 and 30 lb versions (and 40, for that matter). There are MANY threads on SB regarding wing selection and lift calculation, including an equally current one (
http://www.scubaboard.com/forums/basic-scuba-discussions/333502-what-size-wing.html) on the topic. Many of them include posts by Tobin, owner of Deep Sea Supply, and he is a tremendously valuable repository of informtion on the topic. I would either do a search, perhaps using 'wing lift', or PM him directly, at cool_hardware52.