Upto a PA140.2 would fit in most cases that have full-frontal 5.25" bays with no modding.
A PA140.3 wouldn't fit in anything particularly... MountainMods would possibly knock out a new cube large enough for it, but that'd be the only "convenient" option...
Regardless, even if it was to make it beyond the initial PA140.1 prototype that we sent Cathar, it would still be a LONG time before they came to market...