Honestly, I think Fett could take a Predator. For one, while he can't hide visually from the Predator, I can imagine he's a savvy enough bounty hunter to get the drop on the Predator. And seeing as Danny Glover can kill one, Fett can take two. Hell. Cloaking device? Doesn't Fett have infrared in that helmet of his ? In any case, yes, he can do this, assuming he's not in a subway tunnel with one.
Alright, let's get this straight. The Predator has a shoulder canon and a spear gun. Maybe the disc and a netgun. Wrist blades. Excellent strength. Can climb.
Boba Fett is a bounty hunter who has tracked and killed many more species than the Predator. Boba Fett specializes in ultra deadly weaponry, like the Mandalorian wrist darts he has, which are deadlier than anything the Predator uses. Secondly, Boba has a rocketpack, which makes him not some static ground fighter but a moving aerial target. Predator can't hide from Boba and Boba can't hide from him (Unless the armor shields from infrared vision, which wouldn't surprise me). Boba also uses blaster weapons which are faster than the Predator's own laser weapons.
And keep in mind that the Predator's greatest strength comes in its ability to ambush prey. While big and deadly, it is actually exposed in the open and could not fight effectively.