Ket - Welcome to
TBN. You might want to consider registering so that everyone can get more info about you and then can be even more helpful!
You never want to run in
4wd while mowing, even if you have turf tires. If the majority of your seat time is going to be doing finish mowing, you'll definitely want to get turf tires. If you'll be doing a lot of other kinds of work (i.e.
FEL, field cutting, etc.) then you might want to consider R-4's, which are kind of the middle ground between regular Ag tires and turf tires.