My WTB Prowlers worked well down there last year. I would think that aggressive tires would work well b/c you don't have to worry to much about mud/dirt packing in them. Like you said, there is a lot of loose rock.
I think Konabiker's tires worked fine also, which makes me think that maybe you are over thinking your tire situation just a bit. As long as you don't have slicks, I think you should be fine.
There is always someplace in the world dry enough for kick'n up a little dirt.
FIND IT AND LET THE REST OF US KNOW!