Installing a cellular repeater is a good idea to boost cellphone signal.It requires your cellphone to have atleast two network bars -
How to improve cell reception in 5 easy steps -
How to Cure Bad Cell Phone Reception In Rural Areas -
And the best phone to receive signals in remote areas is Nokia.They have launched a series of Windows phone worldwide.But avoid their Symbian and Meego offerings as they are abandoned.
Nokia Lumia 710 is the cheapest model to purchase -
Nokia Lumia 710 indepth review -
Nokia is also going to launch much cheaper(less featured) Windows phone in recent Mobile World Congress.So wait and see what you can choose.
The network connection also depends upon the company who has setup the cellular towers and which phone uses their chipsets.For example-if a rural areas has all its cellular towers setup by ST-Erricson then the phone which have ST-Erricson chipset will catch the signal the most in all cases.In future,Nokia will use ST-Erricson chipsets in their future Windows phone.