and as you know here in Barbados, getting the parts and the custom work will seriously drive the price up...and actually neil's starlet was the first that came to mind which is some serious engineering and fabrication work that is going to run you some major $$$ even for a far more simple set up
i'm not sure if you can take the rear floor pan and gas tank off an ep85 and transfer it to the ep82??...at least that would give you a base for independent suspension, but then again the costs involved...just using some basic calculations i'd say you looking at BDS$5,000/10,000 plus depending on what you want to do, who does the fabrication, importing items, etc...........BUT if one is going to go through all that trouble, then it would make sense to try to adapt a better rear suspension set up from maybe a honda or some other model???!!!
that's why i suggested the coil-overs, braces, struts, roll bars, tires, etc....may land you at the lower cost point and give you much needed improvements with minimal downtime
PS--just for the UK users the currency conversion is about gbp1 = BDS$2.55