I`m going to guess that by "FS`s" you mean independant providers who offers full service.
When I was first looking around i was baffled by the lingo and if it really meant what i thought it did. This link was most helpful:
https://perb.cc/vbulletin/showthread.php?t=53
But to really answer your main question... Yes, the foxes provide FS. Not all provide GFE (kissing both sets of lips as Very Veronica said) so your best bet is to stress GFE if that`s what you want. The phone foxes are very helpful in helping you find the right girl for you, so if you have perferences in terms of the "type" of girl (ethnicity, measurements, etc) state them or you might not get exactly what you want.
They can`t, for legal reasons, go into details with you over the phone so don`t push it. Just rest assured that you will get the full meal deal once you get there. And don`t be surprised if, at the Fox Den front desk, they act coy and tell you to enjoy your "bodyslide." You`ll get more than that.
Other than that look on the carman fox site, pick a few girls you`d like to see and do a perb search on their names and see if stuff comes up. Or type "foxes" (fox doesn`t seem to work) and you`ll get a lot of reviews of a lot of girls.