24 bit is a very useful option because it improves the dynamic range.
The samplerate is a bit of a controversial issue. A lot of pro studios record at "only" 44.1 kHz. Others use 48, 88.2, 192 kHz etc.
Personally I think 44.1 is enough. The latency with higher samplerates will be lower, that's a plus.. but the CPU will have more work to do.
And the tracks will be a lot bigger. In the end you will have to downsample to 44.1 kHz for a CD release if you used a higher samplerate, just don't forget that when you're done.