will depend on budget, and how much power you want from that budget.
now days all the motors have decent aftermarket stuff so you wont have a lot of trouble with parts.
Can get 200kw out of an SR relatively easily, where as a CA will need a bit more to get there.
I've had a CA and an SR, the CA was good fun, bulletproof, but lacked the 'kick' and i couldn't be bothered dumping $$ into it.
SR although its the tractor motor has been reliable and easy power.
i dont have a clue regarding the FJ, but hear good things, just an older motor is all.
can come down to personal preference. just make sure you do your research and dont jump into anything too quickly.
have fun