How much money does a ......
Also what shops around maryland/DC are there that deal with LS1s/T56 trannys?
Kinda depends on what you plan on doing with it. Eventually, parts will wear out.
A standard rebuild kit with a steel 3-4 fork is really all that's "out there", unless you start getting in to billet shafts and whatnot ($$$). I wouldn't hesitate to put a regular T56 behind my motor, I don't think there'd be any problems at all.
(the only things I've done to mine are pro-shifting - it's got no blocker rings - so it goes in to gear faster - but this is not a street friendly setup; and I've got a steel 3-4 fork. No fancy parts here, holds 600+ RWHP on slicks just fine
). 
