If you want to go with chemical ferts, that would be an acceptable choice for veg. Not really good for flowering.
As toasty said, those would be acceptable ferts... You may want to try something with higher N and lower P and K... and then as you move into blooming, switch to higher P and K and lower N. I also wouldn't use MG. I would try something organic, but that is just me...
Pura Vida Organics are really awesome... Grow: 6-4-3 Bloom: 2-6-6 And they aren't too expensive... A little less than $30 a liter... and a liter will go a long way... and its organic, so it will reduce your risk of nute burn... Just thought I would give you my $0.02.
I believe the Big Bloom and Grow Big are organic and the Tiger Bloom is "organic based" so maybe not 100% organic but pretty close. I did use them and they are pretty good.
20-20-20 is equivalent to 10-10-10 or any other value of x. That is the % of each of the major constituent elements in your particular bottle. You will just dilute 20-20-20 more than you dilute 10-10-10, so the final brew that you give your girls will have the same concentration of NPK. N and P and K are all required at all stages of growing, the plants just take them up at different rates at different times. The stuff I buy (when I am not giving my own Russian comfrey fert), BioCanna, contains higher N than P and K in the vegging formula, and higher P and K in the flowering formula. This is useful: http://www.allotment.org.uk/fertilizer/npk-fertilizer.php