plants need 10,000 lumens per sq ft max...at least 4,000. each t5 h/o puts out about 93 lumens per watt... 1 4 ft 55w t5 will be sufficient. check out bulbman.com and also check out "160 watt flourescent grow" thread
Go HID if you can afford a decent fan /cool tube. 400 for your 4 plants or 150 for your single. That is just my opinion. I prefer T5's for plants under 10" or sustaining mothers, anything bigger and give me HO.
400 watts of T5 uses the same electricity as 400 hps/mh.
If your asking how to hook them up you haven't read enough yet.