I think the OP should start small and safe, with say 4 ported UXL-18's, and if he is still unhappy
with the results after that, double it to 8,
and only then
if still unhappy should he invest more money, pouring huge vats of cement permanently fixed in place etc etc.
How many subs has the OP built in the past using drivers as beefy as the UXL/LMS/RE/SI24?
Going from a 12 inch SVS or Velodyne to 8 UXL/LMS's is gonna be one hell of a shock. He needs a reference point to compare.
Nobody should get directly out of cadets and then jump directly into a prestige Mach 10 capable Aurora stealth fighter carrying active 100 megatonne nuclear warheads with fingers to the sky.
You need to start with a Pinto, and then upgrade to 1990 Corvette, and then maybe a single Bugatti.
Nobody should buy 32 Bugatti Veyron's, one for each color of the rainbow, as their first car on their legal birthday; and be found dead the same day having impacted the other side of the dealership parking lot at 300mph because they don't know how to shift or handle 1000hp times 32!!! LOL
That said... no matter what boxes you put 8, 16 or 32 UXL/LMS's in, even if you did it 100% wrong, it is still gonna blow your head off. You can't really mess up with that much overkill.
As Nike says: JUST DO IT!!!