Goody, I'm a budget minded individual as well, so if you can break things down into bite size chunks it's a little friendlier on the pocket book. That's how I did it.
First thing I'd secure is the E-body specific parts; the pedal assembly, 4 speed hump, z-bar. You can install the pedal assembly and hump in the car before you get the other 4 speed parts.
There aren't any cheap musclecar-era 4 speeds, but if you hit the junkyards and watch the '75 to early 80's Dodge Vans and trucks you might be able to come up with an OD transmission for cheap. You may as well try it out, I know you don't like the wider ratio, but I like the OD four speeds myself. With my 3.91 gear set, the OD A-833's 3.09 first gear (non-OD A833s have a 2.65 or 2.66) the car is a rocket ship out of the hole, and the .76 OD lets me cruise the freeway a lot easier, especially with my 26.0" tires. Later if you decide you want the non-OD 23 spline unit, they are completely interchangable.
My local yards get about $120 out the door for a four speed transmission, but my friend once got lucky and got the flywheel, bellhousing, clutch, and OD A-833 tranny for that price! The shifter was extra though. Don't forget to grab the transmission yoke, it's different (larger) than the 904 yoke.
Also E-body specific are the shift rods, and shifter mounting pad. I sucked it up and bought them brand new through eBay, the shifter rods required a little tweaking and I sprung for the billet aluminum shifter mount because I hear the stock cast ones are prone to breakage. Same with the Pistol grip handle.
I ran an aluminum flywheel, Centerforce Dual Friction Clutch, and a scattershield, and wouldn't change it for anything. I drive way too "spirited" to run a stock bellhousing and worry about loosing a foot or toes if something explodes.
I drove my Challenger to work today, and love it. I wouldn't change a thing about my tranny combo.
