I currently own a Samsung E715 which is about the same in signal and battery life. In all honesty the phone is average in signal and in battery life. I've heard no complaints about the E105 though, so it should be a reliable phone, and you should have to worry about defects.

My recommendation for signal right now is going to be Nokia. I know it's not a flip phone, but all the new nokias have an automatic key guard so you don't have to worry about remembering to manually lock your keys, or making accidental calls. If you want a compact phone the Nokia 6610 is going to be the best choice. It should be about the same price as the E105 or maybe cheaper.