Which Leaf Springs to match my Torsion Bars?

Holy crap those Hotchkis look like they're the way to go.

On a side note: I have researched that getting the back of the car down 2" would make a lot more difference than one would think (actually, doing so makes it handle much better was what I learned), but can I run a 27" tire out back if I go with the Hotchkis or XHD's w/ 2" block?

Thinking about a 255/50R17:
http://www.summitracing.com/parts/RIK-11262/

You will not need 2" blocks with the Hotchkis springs. They put the car plenty low.

With 255/50/17 run a 17x8 with 4.5 rear backspacing should be fine.

Even billet spacers are not really desired for handling. Especially something like 2". They put leverage on the axle when you are cornering and hurt locating the rear end side to side. Also, the springs will still have a big arch on them which create rear roll steer. For handling, it's actually better to have them near flat with slight arch.