What's the best current Fido (Canada) cellphone for a fringe reception area?

I've been a Fido subscriber for several years and am pretty happy with the service. I work in a suburban area that has good reception but live in a fringe area. The reception at home is ok if I stand at a window or go outside but inside I get 1 or no bars. I just retired my LG2000 phone and got a SonyEricsson Z310A as a replacement. I like the phone ok but reception is worse than the LG2000. A clerk at a wireless store recommended the SonyEricsson Z310A as the best available for good reception in marginal areas. She also reiterated the fact that Fido/Rogers has the best reception in the Chilliwack River Valley where I live. I'm disappointed in the Z310A to say the least. I've been looking at wireless amplifiers today but they start at $200 plus! Not a viable solution for me. I have 13 more days to return the phone. Does anyone have any ideas on getting better fringe area reception that doesn't cost a fortune or recommend a Fido phone offering better reception that Fido offers? TIA!