I am not having good knowledge on AVRs...but wish to buy one because I love sound. When I read some reviews I felt as if there would be not much improvement in the kind of effect a 7.1/.2 would produce when compared with a 5.1 ( Atleast not worth the money spent on the extra speakers).. Please correct me if I am wrong. Coming to my actual question...in this regard if I wish to buy a 5.1, then can I use the tower speakers or should I settle for the normal front speakers ( similar to the virtual presence speakers)?
A surround system with a higher speaker count simply adds (or attempts to add) to the level of spatial immersion that's achievable. 5.1 is good for home setups, because going to the higher speaker counts a) costs more b) is more difficult to configure correctly.
If you don't know what to pick, then buy a speaker set. And I would advise it in any case, because it's better to leave the speaker matching to the manufacturers. Also standing vs non-standing speakers, it's more of a space/aesthetics issue. According to Dolby specs all speakers except the subwoofer should be full-range speakers. However in practice, the rear speakers can be smaller (and cheaper) and have less bass respose, because in mixes they generally don't carry that much information or bass heavy information compared to the front speakers.
The front speakers should be full range in either case.