for 180bhp, its not that hard, i would start with a

chip,
cam,
pace i/c,
S/S Zorst
boost increase
Setup
stage 1 clutch

U should see 180bhp, and with quite good reliabilty

Gearbox should take it, providing its in good condition, i was running 200bhp through my 150k rst gearbox with no problems, only changed it the other day to a mk6 box while i changed the clutch

listen for whines in gears and crunching 2nd and 3rd gears