Chuck's right. The bar off a roadster is your cheap answer. You could go with a larger one from the aftermarket, but I'm thinking it'd be limited gains, really, unless you're really pushing hard. Even then, there's probably better ways to spend the money.
If it's a RB BGT, you should spend your money lowering it to CB height. THAT will give you the handling you want. Several ways to do it. Fitting a CB crossmember is best, but tends to be the most costly, too.
Anyway, forget about the front tube shock conversions. They're a sick joke that will do NOTHING for your handling whatsoever. Matter of fact, they're worse than good tube shocks.
The coilover conversions are very nice, but that's a lot of money.