Hello all, im hoping someone can help me here as this problem has been doing my head in

recently my 2.0l 8v r reg gti golf started making a lot of noise when idleing, this went away when you pressed down the clutch, ohh thrust bearing i thought, i drove it home and it stated making a total racket, basically like id filled a jar with nuts and was shaking it up and down

i took it too my mechanic and he replaced the clutch and thrust bearing, problem was the person before me had changed the gearbox and clutch for a 1.8 version, now my mechanic didnt know the gearbox was knackerd till he took it off his drive, so basically ive still got a non running car with a new 1.8 clutch, my question is what gearbox do i need too get too match up with the clutch, ive looked around and my guess is a mk 2 1.8 8v gearbox but i really havent got a clue, ive found a 1.8 gearbox on ebay but im not sure that would do the job either :S
http://www.ebay.co.uk/itm/VW-GOLF-MK3-MK4-GEARBOX-MANUAL-1-8L-BREAKING-/110733624880?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19c83d0630#ht_591wt_1396Some help plz!
