There's too many factors when it comes to trades and this situation in general. Like ISBB said, I'd just see if you guys could assume the loans. Otherwise no matter how good of friends you are, if something happens like damage, theft, excessive wear, repairs, etc... who is ultimatley responsible and will one guy get screwed over possibly ruining a friendship?
I don't ever loan my stuff out unless it is to a very good friend that I can trust. I would still never TRADE toys and payments for any period of time- NO way.