Does SIZE Matter?

Alrighty ppl,
Bought 2 x 250w CFL's Red n Blue.

Should i have got ten wee ones.
or
Does the big Girthy CFL's do the damage?

pics? links?

umm http://www.supaprice.co.uk/p/result.jsp?ga=uk7&q=cfl+250w the ones top right in the list compared to the small ones.

Iv got a digi camera in the post so i can take pics of me stealth with the big cfls.