I agree with the point Stan makes in his answer, that replacing these wheels with anything will likely cost in excess of the amount required to buy a new quality case with a wheel configuration that appeals.
I'd look for a case where the wheels are detachable, if you're considering 360 castors, so the wheels can be stowed inside the case and it more easily meets the dimensions rules at check time (they can be remounted as soon as the hand luggage dimension police have moved on :) ).
Alternatively, consider a case with low profile fixed direction (non castoring) wheels. These tend to be the kind of wheels used on inline skates and by virtue of their design (relatively large ball bearings, fixed travel direction, thick ring of rubber forms the tyre and will hence absorb shocks) seem to be more reliable than the tiny-castoring-wheel type I've owned
I do feel your question is almost off topic, but in line with the life hack spirit of the site, if you love the case I would recommend having a go at mounting some wheels or the type I describe (I'm not sure I would bother with castors) - attaching two squares of quality hard wood plywood to act as load spreaders on the inside and outside of the case ( the case becomes sandwiched between the ply) then fix some quality fixed (non castoring) wheels from the hardware store. If you want the most strength, use bolts with self locking nuts and fasten all the way through both sides of the ply (drill a hole and pass the fixing al the way through the sandwich comprising the wheel mount, outer ply, case, inner ply.
If the job is beyond you skill set or tool range, a local handyman should be able to complete it no problem, in about an hour if given a clear plan of what to do- it's probably on par with flat pack furniture assembly in terms of engineering requirements