I guess my concern if I were doing it to my system is how does one stop the pool not emptying its contents into your machine room, but if someone can address that then maybe I could be tempted to have a go. [Probably not - I'm too risk averse - I'm the sort that believes in paying for pros and having been a pro in another profession I have the resources to do that (but I would never knock those that have to or want to look for cheaper solutions]. I think my pump is a bit lower than the top water line of the pool - maybe you have to partially empty the pool in those circs but I'll bet the pool builders have some tricks to circumvent that.
I am sure you need to fix the pump more steadily than you describe its current fixing status. You risk vibrations being pushed around the pipework and eventually compromising some seals (I would guess). I'd expect to build a concrete platform/block using formwork onto the floor to provide a stable base; should be within a decent builder's competence. Whether they are good at getting the alignment right is down to their experience/professionalism I guess. Alternatively the pump's input and output pipework can possibly be remodelled so that it reaches down to a pump fixed to the existing floor level.
Emaux pumps have always done the job for me but no doubt Bagwain (an experienced pro who comments on this forum) will be along to tell you about something he believes to be better. As I understand it Hayward are good quality, but expensive in Thailand.
I have a 90,000 litre pool (including reserve tank) and Swimming Pools Thailand advised me to use a 1.0 HP Emaux pump at the initial build stage. I got to thinking it was a little bit underpowered, so I upgraded to 1.5 HP when I replaced it after 10 years (the old one was by then leaking a bit past the main joint seal half way along the pump; could have tried new seals but wanted to upgrade anyway to ensure I got the right solution without paying for a second visit if new seals didn't solve the problem after 1st visit).
As before - good luck!