Hey,
If money anf\d speed's the issue here, I'll suggest putting in another motor, like an L series, or sentra twincam motor bought 2nd hand from places like Jap Motors, Motor exchange, etc here in SA.
I'm sure yould like to have power like the guys youve seen here In SA with the 1400 bakkies,
and believe me,those guys at the races have mainly put in L series, sentra,and rotary engines.
Dont get me wrong, the a14 motor can be worked, but it wouldnt last as long as you would like it to and then yould be dissapointed with money spent on it , rather go bigger motor.
Oh and as reboring, this will normally be decided on, if you have a ridge on the block.
I would suggest,taking it to the engineers to have it checked out if there a ridgethat cannot be honed out, they will then decide as to how many Thou to rebore and size of pistons to use.
Just letting you know about my trials and errors and successes.