substrate for lileopsis & r. macrandra

Hi all,

I was thinking of adding lileopsis (sp.?) and rotala macrandra to my 
desktop 5.5 gal tank.  What would be a good soil to use with vermiculate?
Potting soil or soil from my backyard garden which has a lot of clay in it?

Also, would 30 watts of daylight flourescent be enough for r. macrandra in
a 5.5 gal?  If so, should I pot it?

Many thanks,

Stephen Morrison in Batavia Illinois