2 part ?..seedbanks..yield

Ive seen nirvana, amsterdam marijuana seeds, serious seeds, greenhouse seeds websites. What are some of your experience with these guys or got anyone better? Also a quick question on lights/yield. Is my potential yield directly effected by the strength of light I use? I was gonna use a 250 MH and HPS for 4 plants at a time but not if its gonna take a big bite off my crop. And while I am on it does anyone know the energy difference between a 400 watt and 250? i.e. electric bill difference? Not to noticable?

I ordered some Ceres seeds and they seem to be pretty good Very discreet packaging and pretty quick shipment.

i wanna know about 250 to 400 watts also . Anyone know diff each plant might produce. I wanna know what i might be missing w/ out the 400.
thanks in advance

It is said that indoors, plants will average about .7gram per watt... so you will get less with a 250 than a 400... especially growing four plants under 1 light.

I dont think that 250 is gonna cut it for 4. maybe 3.

sensibleseeds.com has always been great, never taken more than 7 days