Multi Genre "Dungeon" Crawl

[clig76]

I was searching around the internet and stumbled across the combat system for Gurps 4e. It looks amazing. I have been looking for a system to use a cross-genre "Dungeon Crawl".

I really enjoy creating characters, taking them through combat scenerios, gaining experience and leveling up.

Anyway, after a brief look at the system (and all its genres) it really looks like what I have been looking for. I do however have a few questions for you experts out there...

1) The battles are played on hex map, correct?
2) Is facing important (flanking etc)
3) How many books do I need to start a basic game?

Thanks,
Curt

PS. I know using such a great RPG system to create a "Beat Em Up" game can be seen as blasphemous. Please ease up on the bashing. Im just looking for advice.