I'll have to agree that printing to film instead of casey's translucency is going to greatly improve your halftones, and yes, you can indeed expose with most anything if you are careful enough, but do yourself a favor and look around for some better used exposure equipment, it will just make your life easier so you can get more out. I started out working at a midsized shop that had top of the line, at the time, exposure equipment, (an arc lamp, LOL) and when I saw small tube units, I knew the better exposure equipment did a better job, so we never looked for anything other than Metal Halide when we started our own shop...
Steve