WBS, 3800perf, ZZP,Intense, Milzy, Cartuning, and Overkill are all rep. shops.
FWIW I prefer Intense/Overkill (b/c of the customer service i have had w/ them)
The topswap kit you listed will fit, but it is difficult to install (basically have to drop the cradle to swap the crank pulley) and will be a project!
ZZP sells another version of it using stock L36 (N/A) heads w/ a modified intake
The S/C will be harder on your stock trans then a TC is, BUT the TC will cost more... I, not saying youll have issues, just relaying some info
From what i have heard there are a few people who have bought 3800Perf PCMs who werent 100% satisfied w/ them, and eventually went to ZZP or another company afterwards.
Either mod will net you lower gas milage, due to the fact you'll grow a lead foot as an end result

,That being said, I still average 26mpg w/ my SC'd Imp.
I guess the biggest question would be who is installing the mod for you? Skill level? Location?
Theres quite a few local WBody groups that are usually good for having guys who have modded/willing to lend a hand.
Also just so you know, AFAIK, all the parts you'd be getting on a top swap would be used, might want to double check w/ each vendor though.
Once you go with either of these ods, you will want to start saving either fir a properly built trans ($1500+) or atleast a HD Diff upgrade.
$900 + install kit isnt that bad for a topswap kit though
