It is a very neat car that one. My advice would be to not do anything that can't be undone. There would have to be 100 ke70's out there to every ke1x sedan.
Go subtle, get a set of those 14x5.5" tarago/celica steelies redrilled. Fit a set of decent 185/60 tyres, whitewall them and fit your crown hubcaps. The thing will look sweet and have a huge improvement in cornering power over gay 12" tyres.
Spend your cash on suspension mods that actually make the car handle better, and on a tough turboed K series motor or something. The car may not look as fast with this route, but it will sure go and handle a lot better than the same cash spent on poser spec mods.