switching a 21g from fresh to salt

after some thought I think I'm gonna go with the aquaclear 30 and perhaps make a AC70 mod refuge during my cycle. I think I'm gonna start with a clownfish and work towards a royal gramma, firefish and maybe a barnacle blenny but probably a fish a month starting with the clown... once its cycled.

I am going to start with just a FOWLR setup and work my lighting towards a softie setup in the future. Maybe start with some LED's if I catch a sale during my cycle. I think the T8's will do for the cycle period since they only need to be on for a few hours a day (mostly for me to stare at the rock to convince myself I'm really taking the plunge, haha).

I'm thinking of about an inch dry sand and maybe 15lbs dry rock with a couple pounds live rock if I can find some good quality stuff at my lfs.

Any thoughts?