Right driveshafts a proper way of doing them is to cut both in half to the desired length then sleeve them and seem weld it with a tig welder these would be strong and is done alot sometimes with the v-tec minis
Youd need to put strengthening plates all over the chassis to take the extra acceleration force or you would kill the car and all your work
the v-tec conversions on minis and cinqs IMO are over priced theyve done it once they can do it again far easier
personally as said before id use a vaux XE engine as there smaller which helps when fitting it in, are very tuneable, dont have to be revved anywhere near as hard, cheaper to buy and for parts
Go buy a cavalier GSI then go buy an 899 cinq put the engine box and wiring loom with ecu in the cinq and all youve got to worry about is strengthening plates (google nova 2.0 conversons which will give plenty of help) and engine mounts
wayne