20V MK1 Engine Swap all i will need?

20V MK1 Engine Swap, reason, find, tops, silver, black, gearbox, clutch, give, mista, jordan, combo, engine, gear, loom, exhaust$1100, halfcut, aw11, worth, people, $1450, cost, labour

i am going to put a 20V black top in my 85 AW11. i am getting the engine, gear box, ECU and loom ($1450). i know i will need a new exhaust($1100) but is there anything i dont know about yet? i can get a halfcut but it would be about 1g more and will cost in labour to take the 20V out, would it be worth it? most people here seem to go for silver tops, is that because that is all you can find in the USA or is there another reason? do i use my gearbox and clutch or do i use the one from the 20V or