Where is best place to buy air conditioners

I need to buy 3 air conditioners for HOME (not commercial) use.

I want:

1. good quality,

2. good bargain

3. good service + cleaning for future (I have read previous posts on this forum about poor maintenance service).

I've seen them on top floor of central world but I assume these are more expensive???

I've seen http://www.youtube.com/watch?v=5sxKaz2TqDs

Any suggestions re companies to deal with:

e.g.,

http://www.aircongenie.com/

I've googled air conditioners bangkok but have not found a lot of listings.