2 or more Range Extenders for better coverage - is it possible?

Ideally you want APs with both a and b/g so you can bridge using one without affecting the throughput of the other as they use different frequencies.  Typically a is the 'backbone' with clients connecting to b/g.

Note:  Wireless overlap causes higher error rates as the signals interfere with each other.  This typically manifests itself in lower connection rates/reduced range.

And now to actually answer your question!

"Is it possible to use 2 or more Range Extenders with one Wireless router to get better reception in one large office/house/apartment?"
Yes.

"Will this setup affect connection speed/max speed wireless adapters will communicate with particular AP (which will be actually the range extendes)?"
Yes.  Maximum throughput will be affected

"I saw also somewhere here @ EE that it's possible to use 2 or more wireless router in "bridged" mode to get the same result, is it similar setup or something different?"
There is a difference between a repeater and a bridge - both could be described as a range extender.

" Which way is better?"
Depends on your requirements and the relevent importance of certain factors (cost, complexity, etc...).  I'd favour a bridge.

"Thanks."
No problem;  ;)

PS: Out of interest do you have a particular make/model of AP already in use or in mind?

In my case I can't replace existing router which is just b/g (TRENDNET TEW-633GR). So should I get just one range extender or one reouter whcih will operate in bridged mode? Please, let me knwo which model will work with my Trendnet. Thanks.