mate fitting an A15 is piss easy, check out 1200rallycar's photoalbum, he's posted a pic of an adapter plate, it looks dead simple to make. I was lucky and already had an adapter plate for my A15 and 5 speeds are easy too, just bolt it up an d then hold up it up with a jack or something and draw up an adapter plate to hold it all up, then take that to a steel fabricator place and they'll knock one up for ya in no time. Well thats alll I did to fit my 5sp.
cheers
Damo