After doing a good amount of research on web hosting companies located around the world I decided not to go for a server in US or in any other part of the world rather to go for a Tier 1 ISP in UK. I opted to go for a server rather than a shared hosting option because of the following reasons:
1) We can install whatever software we want.
2) Our site do not have to share the extra burden of other websites on the same webserver.
3) Our site won’t crash if some other website starts misbehaving due to some bug in their code or any other problem.
Anyway, now I have to install some additional softwares and reconfigure the server according to our requirement. If everything goes well then i dont think it should take more than 2-3 days.