@ blaze, i use 400mh but i like my plants at least a foot tall before i put them under it, i grow my seedlings/clones under a 2 x 55 watt cfl until they hit around that height, i feel that the mh or hps is just a bit too intense below that buddy.
@ mistah j, be careful of ur miracle gro, its not an easy soil to work with( i use it all the time myself though), it has slow release nutes in it and they can easily burn ur plants when young and its released when u water it, i never start seeds or clones in it i use a nute free seedling soil, just a cheap one from any garden store will do; add a little perlite.