So was going to replace the u joints in my 98 grand Cherokee front axles but wondering since I am not an off road person if I can go with new axles with the CV joint?

I would just replace the U joints, there is no advantage to having CVs and they are weaker and more expensive.

Well I can get both axle assemblies with CV joints for $130 or I can get one U-joint style for $200. But I think I will just replace the U-joints and pax like $40.