There is no magical SS gear ratio that you can go "really quick" and climb easily. For my 29er, I run 33x20 and can get up most of the steep stuff. Flat terrain kind of sucks as far as speed.
If your chain falls off, you just need to adjust your deraileur. But SS is nice, because you're not messing with all that stuff. If I were you, I'd get a SS specific bike instead of converting. I have heard of people that have converted with a SS kit and still had problems with the chain falling off. This is why I like my MC with track ends much better. Simple and efficient. No slider slippage or EBB creak.
If your chain falls off, you just need to adjust your deraileur. But SS is nice, because you're not messing with all that stuff. If I were you, I'd get a SS specific bike instead of converting. I have heard of people that have converted with a SS kit and still had problems with the chain falling off. This is why I like my MC with track ends much better. Simple and efficient. No slider slippage or EBB creak.