I have one more option that may interest you (possibly). Chevy used a four speed that is more closely associated with big engines in a small car Chrysler (think Sox and Martin's four year dominance of the Pro Stock class with a Dodge dart powered by a 426 Hemi). The A833 New Process transmission was used from 1981-'87 by Chevy in C and G-20 and 30 pick-ups and vans, but not as a four speed. Instead they flipped third gear around and made it 1:1 and converted the final drive into a 30% reduction over drive.
You can read about the trans being modified to fit a Chevy here:
You can still find them in junk yards and even though this is a very nice example of a rebuilt tranny it still requires a Special Chevy to Chrysler bell housing (Chevy used a cast aluminum bell-housing to accomplish this, but I strongly recommend a steel SFI rated puke can for safety reasons: even if your racing days are behind you). This bell housing is set up for an eleven inch clutch but you can still use a ten and a half inside the bell housing if that is what you have, It just has to be for a Chrysler 23 spline input shaft instead of the older (pre-1969) ten spline input shaft. and it uses a Chrysler 30 spline out put shaft yoke with a 1350 U-joint bearing because it was out of a "heavy duty" light truck (van). This is why it has such a steep first gear (handy for those burn outs).
I recommend the junk yard route as a source of everything you will need to bolt this combination into your car. (bell housing, fly wheel, starter motor, clutch and pressure plate, throw out bearing, and the throw out bearing fork, tranny along with the shifter, and the transmission out put yoke with U-joint, or the whole drive shaft if you can get it for free). At a U-pull yard on any given Saturday you can get all of these things for scrap value assuming you can find the correct van in the yard. This would be your cheapest route if you can find one.
If you were thinking about buying the rebuilt unit off e-Bay and everything else that is missing new, consider instead an Autogear rebuilt Muncie four speed with a super case and cast iron mid plate that uses a custom set of gears to get you a four speed overdrive similar to the A-833 tranny. This way everything bolts up as it would with any other Muncie.
Look for the M21Y option at the bottom of the page. Last time I inquired this brand new, bullet proof Muncie, was running around $1,960 but that was over two years ago so prices have probably risen by now; but not as high as a new T-56 or a TKO 500 I would wager.