We went with tumbled travertine and it's not to bad slip-wise.....not the grip of concrete but in 7 years with kids running around no one has ever slipped. we did the whole patio and the walk ways around the house the same and it's help up nicely.
On cost we ended up paying about 3.35/sqft for the stone itself. I found web site for a place in Turkey (I'd have to dig a bit for a link) that was willing to send references (which checked out) and they handled the shipping to the US for me. There was a little stress with "our container was tagged for inspection" , "oh, now the inspection is done but it's too late to get ti off the dock so you own storage/rental", "the truck will be there by 10Am...WAIT! you said I'd get 24 hours notice! sh*t! I need to get a fork truck delivered in 2 hours!"
but once we got past all that the final cost was about $3.35 which has 1/2 what the local stone place quoted me and my wife was happy that she got what she wanted so that's all the matters I guess.