Re: 9" ratio
I saw a supra gearbox in the trading post this week for $620. I think he was in NSW. Speak to Rod Hadfield about a bellhousing/clutch/crossmember. He probably has a kit available but I reckon it won't be cheap.
If I may make a suggestion, unless you are doing a lot of highway miles I wouldn't bother with a five speed, just get a toploader and save yourself some bucks. Parts are easy to source and everything bolts straight in. No need to dick around with shifters, speedo gears, crossmembers, starter motors and the like and unless you are making big horsepower they are hard to break.
If you are after a 9" and you are in Melbourne, I have an XY width LSD 3.25 ratio with finned GT drums and powdercoated housing for sale for $700. Nice unit, cheap, cheap!