Dedicated racecar? YES!!!
Faster than 10.00….. meh, not sure I care to go there to be perfectly honest. Things get a lot more complicated and expensive beyond that line. I’ve always felt like bottom 10’s is the sweet spot of fun per dollar. So the big question becomes the cage. Is it worth it to add 50 - 60 lbs when you don’t intend to go fast enough to need it? I know the argument is that someday when the car gets there, you will likely feel different; So build it now. I get that. But the added expense and weight…..
My build was intended to happily be a mid 10 car, for REAL street fun, but............ with what I presume was a tailwind at one of my favorite tracks, it dipped and blipped a 9.97 time slip. Thereafter, it has loitered in the very low 10's which is realistic and within the militarized or demilitarized zone as you say.
Things get expensive and time consuming maintenance duties get amplified in the 9's. It's great to be in that zone, but at what cost$.
I would safely say, that being that you are basically semi- starting with a clean slate, budget and time is a concern, so perhaps rebuild it to within the range that you already had it arranged for. If it surprises you with a faster clip, then dress accordingly for the occasion.
My friends REAL STREET DRIVEN, RADIO PLAYING AND NO NOS small block (408 ci) Duster was built to be happily in the low 11's, but his car woke him up with a 10.50 blast one day. He's a seasoned Tree killing points chaser and as much as the track officials knew and respected him, they gave him THE LOOK and he had to dial it back to an 11.50 dial just to be safe with no roll bar or cage. I helped lighten it a little, but not much.
Your car will be nice when it comes back.