Thing is, I don't know how many lights should I get. 1x40W CFL 2700k in flower won't suffice right?
I've found that there are many different ways to achieve a similar goal.
With that size tent, you could go with a 250 watt cfl, but if you are growing with a tight budget, you could get some 23w or 40 watt from Lowes.
You could grow seed to harvest with a 23w bulb and babies in solo cups if you wanted to, but your results would reflect the lack of light. Either you would have a small yield of tight bud or "airy' bud.
Your tent is roughly 4 feet high. and 2ft by 2ft. What size pots you should use will greatly depend on what lights you are going to use.
Cause a 4 foot high tent, minus say 8-12 inches for your light(if you are using a reflector, possibly less if you are not) Minus another few inches or more, if you are using a high wattage CFL( the 125-250 watt cfls get pretty hot. The 23/40 watt ones you can (almost) let the plant touch the light.) Minus whatever vertical space your pot with soil takes up, say around 6 inches for a 1 gallon pot(milkjug**WITH HOLES IN THE BOTTOM)
So out of 4 feet, you are left with around 2-3feet of usable space for your plant.
(Edit: as an afterthought, if this is just an experimental 1st grow, I would reccomend using 23 or 40 watt cfls. It will minimize heat and also be cheap, although you will have to 'rig' up a fixture for your bulbs OR if you can ventilate that tent of yours, you could get an All in One 150 watt HPS by SunSystems for around 60$ but you may would have to grow our NL in a solo cup and flower soon after she germinates)
Are you able to tell us a round-a-bout budget for your lights?