I have a 12v with compounds, studs, o-rings, Helix-2 cam, springs, etc. twin disk clutch, billet input, Spearco intercooler, fluidampr, tuned injeciton pump, blah blah, it'll run faster than my friend's '97 'Vette.
Get a 12 valve if you want it to live under power. The VP44 will die on you, they really can't be made to fuel hard up to 4k, and even at that high of rpm, you need very epxpensive valvesprings to make that 24valve live up there.
I don't know exactly how high mine will rev, because the tach stops at 4k, and my multimeter won't keep a record of peak rpm. Anyway, the one major disadvantage I see about the 12v is that the injection timing is fixed. I don't really like this. Mine is set at 23 degrees, which makes it gutless down low, but kick you in the ass at about 2500 rpm. If it had a timing curve, like is do-able in the newer trucks it could pull hard all the way up.
I'm planning to back the timing off a little pretty soon, as I don't spend a ton if time up in the revs anyway.
My next truck will most likely be a Common Rail, and it won't be hot rodded too much.
I have about 200k on mine with daily trips to 4000 rpm and 60psi of boost.
Runs like a top, but I need more crankcase ventilation . . . at that high of engine output there are a lot of gases that need to be vented, and I'm leaking from everywhere now. My driveway hates me, lol.