For Boost. - i'd go with an LS vtec motor.
Now to make that LS motor "Vtec" you will need a bseries Vtec head it can be (B16) or (b18c) Gsr "go for the best one you can afford."
This is what a B16 Head looks like! ^
This Is an lsvtec turbo honda! you can see that power !
NOW THE REAL DEAL?
If you want to go "All Motor"
i would go with an H22A or a K20. Heres what they look like
H22 -
k20
Now you can spice it up if you want and add some Nos
And hell yeah it will be heck of a fun ride..
Also The best website for me is ALL YOUR CAR NEEDS AND PARTS