Lighting, MH vs. Florescent

I'm (still) planning and scheming my next tank.  With my budget, I have to
enjoy the planning process long before I get to enjoy the tank.  What I'm
currently thinking about is lighting.

Since I'm thinking of going with a 75gal, I gather that I'll need more than
200W of light.  If I went the florescent route, I would have to have 5 or 6
bulbs.   Dollar-signs flash before my eyes as I think of replacing
vita-lights or something like that every 6 months.  I have many questions,
here are but a few:
+  How long do MH bulbs last?
+  How many would I need?
+  How much do the bulbs and ballasts cost (ballpark)?

In short, from a cost perspective, might this be the way to go?  I won't be
able to hang them pendant-style, but I have access to a shop, and I have a
couple "muffin blowers" (small 110v fans designed, in this case, for
photocopiers), so I assume I could build a housing.

Also, I know I've read about it somewhere, but what does the "degree"
designation mean when applied to bulbs.

Thanks for your help now, in the past, and in the future.