Some things that might help (Pity me I'm still using Sonar 3).

I double tracking:
Duplicate your mono track and pan hard left and right
Tweak the virtual tone by re-amping the tone of your double track
Tweak the EQ of on of the pairs
Add a little delay to one of the tracks. The exact amount will be dictated by the tempo of the song however it is quite easy to work out.

II Compression:
Squeeze those dynamics for a fatter Sound ! The Time works Compressor X that comes with Sonar is great !