what is the best overdrive transmission for a Duster

Man there is no easy solution. I like the gear vendors Idea if it were 1200 or less but 2800 is a bit steep for me. Found a 1999 dodge on CL and it has the overdrive transmission, the guy wants $650 for it but I also don't want to spend a week installing it. I think I am going to just keep my eyes peeled for a 76 833 with the overdrive and someday do that swap.
Thanks again guys