T5 fluorescent

I'm looking for some vegative lights. Is there a difference between regular t5's and t5 grow lights?
The lights I was looking at in the grow shop were £35 each, but I found ones in a light bulb shop for £12. If they're 6500k, will they work?

And should I get 2 6500k's for vegative, or should I get 1 6500k and 1 2700k

Cheers

how many plants?
What strain?

I got a T5 high output grow light a few days ago for $40/ single bulb with the hood. They make a dual light for $80. They also make a T5 setup with 4 bulbs for $179 that will put down some massive vegging. Its 5am here and im tired so the math is up to you. But its something like 18GBp/single... 36GBP/dual... 85GBP/quad but i think you MAY need a ballast for that one.
And NOW they make "bloom bulbs" so that when its time to flower you can buy seperate bulbs to swap in to the hood to flower with instread of using an HPS setup.

There is a difference between T5 shop lights and T5 grow light. You need a T5 that says "high output" or "cool blue"

Thanks for that. The lights I was looking at probably weren't high output ones so.

Seeds are four white widow's. I have a 400w HPS, so I only need the T5 for vegative.

Ya if your starting from seed T5 is deff the way to go. i dont know if i would try 4 plants with just a single bulb but one of the 2 bulb setups should be enough.