The biggest issue you'll face is that the auto is controlled by the ecu. You could run the 26 off the 25 ecu with either an SAFC to put 2 afm signals into 1 or a selin dual maf translator kit. There is some jiggery pokery to get the tps and iac to work correctly on the 26 using the 25 computer.
The up side is that series 1 auto stageas go for next to nothing for one that has a ratty body.
You could even set the auto up on an aftermarket controller, but I'm uncertain on cost.