Yeah, the 250s are fine. Quit worrying about it! I would consider sending back the reflectors, though, and getting the PFO parallel ones. This will result in better light going into your tank more evenly than if you keep the same reflectors and switch to 400s. If you don't believe it, check out Sanjay Joshi's analysis of reflectors. There's a BIG difference, and the spiderlight tested lousy.

I'm a little grumpy because I've been working like a maniac to get this big skimmer finished. It looks great, though, I must say.