Martian Mean Green is hands down my fav sativa, I smoked it at the 2006 cannabis cup, the breeders Don and Aron from D&A genetics.
MMG is suposed to never make a person tired, I smoked it the most while I was there, as it gave me a nice enegertic soaring high.
I have tried some other D&A seeds over here in the US, and it was not as good. Sometimes when growing out seeds it takes a little bit to find the right phenotype you are looking for, as opposed to growing out a clone from strain that is well known.

For instance if you got ten seeds, several may finish later than others, some may be stronger, etc... Shorter/ taller.
Big yield, small yield.

Super Silver Haze is really nice as well, great sativa..
I personally don't like dealing with some sativas, the long flowering time gets to me.

Yes you can start under fluro ad then put under the 250.
Also you can grow out bud under a MH, it might not be as large of a yield, but I have heard several growers saying the quality of bud grown under a MH is slightly better than HPS.(I personally have never tried.)

A lot of different preferences and opinions.
( so many different ways to grow this plant)