That's really a bit of a vague question, so here's a couple to have a think about.

Is this a dedicated showpiece with detuned blown 426 hemi?
Is it to be powered by a turbo'd & blown A12 running on nitro instead?
Other engine?
Is it some rotted old hulk with 12" tyres & a bad engine instalation, or something in between?
Is it intended to be used as a commuter?
I know you said 'driveable' but is it intended to be legal?
Will you be running slicks at the track.
What will be the final weight?
Auto, manual, or special drag transmission?
Leaf spring suspension or four link?
Ladder bars?
Wheelie bars?
Other?
Can you 'drive' [as in, experienced drag race driver]
Do you know anything about cars at all?
Is this a big budget project, or shoestring?
Can you build this car in a halfway decent workshop, or will it be a backyard job with crescent wrench & fenceing wire?

The answers to these & many other questions will determine what kind of performance you can expect from the finished product, but the question, as asked, really is unanswerable.

As to whether it would be streetable, that depends on the donk, if it needs to be really cammy and reving its tits off to make 300hp it might make for a painful daily driver but if its doing it in a relaxed fashion like say a 426 Hemi would then it would be a joy on the street, I dont know what times a 700kg car would do with 300hp but it would be beating everything else on the road off at the traffic lights.

geez mate theres alot of of factors to take into acount there maybe b a bit more specific.id say too fast for u, and me.

theoritically, what times would a ute with 300hp run? and would it be streetable