General vs. Niche; or how About Satellite Sites?

Okay, I'm a fan of brief, so just real quickly:

I'm living in Vegas - rather big town. So, I'm think I should do a niche site (community type with a twist). However, I've been advised to also go after all businesses that are already advertsing (indicating an interest), which makes sense.

So, what about going ahead and doing a general site, but with "satellite niche sites," which could give some business owners two sites they could be on, and/or the site could both be linked?

I'm thinking I could actually do niche sites for several major industries plus a general site, thus receiving and providing the best of both worlds. Well, what do you think about that?

And then secondly, should I break it down into areas (seeing that it's such a big town) in addition to the niches? I.E., Northwest, Southwest, Henderson, North LV, ect.? Or would niching it be sufficient? Would it be better to (1)go with separate websites for areas, (2)provide links on the one bigger site to areas (especially on a niche site) or (3) just don't worry about areas, but provide addresses?

Well, I think you get the picture of what I'm trying to accomplish, and the best method. So, I'm seeking the best advice humanly possible from Warriors (the best site in the world for this type of advice); please respond, thanks!!