I've replied to the oil question in your other thread, Bob. It is mainly a matter of figuring out whether Eaton is one of the hydraulic equipment makers who is happy with the use of engine oil in their light duty hydrostatic transmissions, which is a popular approach. Remember though, do not mix synthetic hydraulic fluid with engine oil. You might find this interesting:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1840482

Personally I'm used to being told to use ordinary ATF in things like backhoes, front loaders etc, but engine oil in tractor PTO hydraulics. However, light duty hydrostatics are quite a bit flimsier than industrial equipment like that.