I'm thinking about growing 2-4 lowryder #2's or diesel ryders (if those get back on stock) in a 50cm x 50cm x 80cm (19.5" x 19.5" x 31.5") cab with cfl's, how much wattage I would need to get about an ounce? Would 125w or 200w econolite (or envirolite, I don't really know the difference between those two) be enough? Or two of those ~100w clamp on lights?

The more the better. In the past i used 4 26w cfls for 2 lowryder 2's and got an 21 grams. I used General Hydroponics nutes.

105-125 watt is definitely enough for 2 decent plants. Going to the 200+w range will give you BIGGER BIGS!

A tip: Cone reflectors suck! Know those reflectors they put over floros? Bingo! White powder-coated aluminum.

Based on 20kLux(actual daylight)... you'd ideally want at least two 200W CFL for big bud production. Though two-four 105w bulbs would probably do better for coverage.

I won't go with more than 200w, since the electricity prices got more expencive now ( .37 cents) , I may get something like this, wou;d it be possible to get 20-30 grams + seeds?

If u sell a couple of gramms cheap to a friend that will cover the cost of the electric no worries.. and u better off with 2x 125 watts as the 125 are more efficiant than the larger.. foe even better efficiancy u could go for a 6 strip T5 2ft long setup with multi spectrum flouro,s and minumum 40% more efficiant.. 144 watts of T5 will outgun 220watts enviro and some!!!

At the moment u can buy complete setup with ballast and reflctors for £65 including delivery 6 strip T5 ecolites 144watt multi spectrum flouros.(. 1200k, etc, etc including the newer purple specs that have shown to boost fruits and resins.. i got one on the way.. cant bloody wait!!!

Can you post the link where you've bought them from?