Are you planning on cloning or growing from scratch? I like trying different strains and not being stuck with just one flavor.
If I was going to try for a perpetual grow I would flower 2 at a time, 12/12 from seed and start 2 more every time you chop 2. You could even just flower one at a time if you really didn't want to go over your 2.5. 12/12 from seeds usually yeild around 2oz.
Or you could clone a mother and go that route if you want the same meds all the time.
I have a couple of blue cheese clones right now and I'll be keeping one as a mother. I'd like to put the other to flower now, but I'm not sure if I can since the grow room took longer to set up than I thought and they're both getting pretty big (20"). I'm worried it will grow too tall in flower.
Anyhow, I may grow or get a clone of another strain at some point just to have two different kinds going, but I don't think I would do much more than that since each strain is at least one more mother, which uses up one of the ridiculously low 12 plants we're limited to.
I will probably avoid growing from seed since they're too expensive and I don't even want to think about dealing with trying to do males and seeds too.
.
Fry, that's an interesting setup. I was thinking of going more with a sea of green type thing and starting flower without vegging too much. But now that I think about it, vegging a bit longer and doing fewer but bigger plants is obviously a better way to keep the plant count down. When you say "groups" how many plants are you talking about? I was thinking my max number in flower at a time would be 4, otherwise with the clones and mothers it seems like I'll be above limit.