1-Yes it's 100% doable, people install 3S-FE, 3S-GTE, blacktops and silvertops in RWD cars, those are all FWD engines installed longitudinally in RWD configuration. I've seen a 7A-GE (7A-FE block with a blacktop head) in a KE30, 7A-FE in a KE70, 4E-FTE in a KP60 and numerous 4A-GE and 3S-FE in Corollas and Starlets and whatnot. All these are FWD engines mated to either T-50 or WXX boxes.
2-4E-FE will be expensie to get and will not have enough oomph. Go for a 4A-GE, any version will do, these are cheaper nowadays. Mate it to a T-50, get compatible diff gears and you're set. Beware though, T-50 for 4A engines are harder to find.