in most cases a torsen diff will make the car handle worse I would save your money.
try this setup I found on the starting grid it should get you in the ballpark
Front end: New Shocks with 1.4 pistons(white) 70wt Associeted oil.
Blue springs, upper and lower "A" Block (red Kit Block)(old "a" block,
not the new front shock tower with red upper "a" to match) I use the
Plastic upper "A" works fine,with the Racers edge front tower.
22 Degree Caster Block.
Few degrees tow out.
15mm of ride hight clips in the front,One 10mm and one 5mm,(or if your
using the Racers edge shock bottoms,13mm clips because the bottoms add
Rear end: new shocks with 1.4(white) with 40 wt Associeted oil
8mm ride hight clips(or 6mm with racers edge bottoms)
Rear 3 degree tow in,2degree(gold)Anti-squat, Rear hubs back.
All shock and camber postions stock Kit positions..
Diff oil 5000,7000,1000 front to rear standard(non lsd
also try crimefighter tires they seem to work everywhere