First time salt questions

[Doormatt]

Hey everyone! After lurking around forums for the past few years, I've finally decided to take the plunge into salt. As soon as I sell off my existing freshwater livestock, I'm going to be converting my 37G into a reef tank.

My question at this point is about the lighting. Right now, I'm thinking of going with a single 250W 10,000K MH and 110W of PC lighting. Using the (assumed pointless) WPG measure, this gives me ~9.7 WPG, and since I'll have a ~5" DSB, the bottom of the tank should be only 14" deep.

I suppose my questions are:

1) Is this lighting sufficent for most corals?
2) I'm unsure if Acitincs are just for looks, or actually help coraline growth.
3) If I use a ventilated hood, should I have a heat problem?
4) Does anyone in the surrey area not use RO/DI water for their Reef tanks, and if so, do you have any problems?

Thanks so much!