I'd recommend a 2002 or later complete motor and tranny pullout. Yes you can add a tranny cooler, electric fans, fuel pump and wiring harness unless you decide to mod the factory harness. If you have the money go for the LS1 or LS2 for gas mileage and horsepower. You can use your factory motor mounts but you'll have to buy or make adapter plates for them.

BTW, if you post on the weekends sometimes it takes a little time to get answers. You aren't being ignored.