Original Post
If you are planning to use with a rear engine - you'd be better off with a pre-73 "tail shifter" 914 transmission (It's really off to side but no nearly as much so as the '73 upside shifters). The tail shifters are cheaper too since in a 914 the side shifters are more precise and hence a common upgrade for earlier cars. You will need the 5 speed shifter too and the starter (or T1 AT starter --- with no support bearing requirement).
In US you can get one for avg of $250 ($100-500 range for used). $800 seems high even for CA $ ??? 914's rust out at an alarming rate so they are plentiful. In addition you will need to flip the R&P so you don't have 5 speeds in reverse. Change venting and add a 912/911 901 nose cone (or machined repro). Oh, and construct a mounting cradle and clearance the chassis some. Suspect cost for above to total $2k - still cheaper than the Gene Berg 5 speed though.