if you have an unlimited budget and a full comprehention of building then i would say buy a used formula block and assemble it with the stroke, lift and all the other ratios you need for a high rev but consider this, the original l28 blocks and are easy to modify and cost far less then finding and salvaging an exotic engine. my personal opinion is that the l28 has all the highreving and sound you want.
drop some carbs shorten the stroke, add the mikuni's or webbers (tuned right of course) and add the velocity stacks with the right exhaust and you'll have the sound you've been hunting for
theres a dude that claims he's stroked and bored his to a 3.1 on youtube.com his sounds great and i think thats the sound your looking for with out the weight and cost
i have an 81 z that will get close to 8k without popping and sound great with an open exhaust (no cat)
good luck