The 07 Precedent has a FE350
It's a pretty strong engine (I have one in my DS)
With the proper adjustments it could tow a 21' boat, no problem...
(in, and out of the water might be a different story!)
but, from what I've been reading lately,
the aftermarket items for the Precedents are few, and far between right now...
so it might be an idea for you to fabricate a hitch, or find someone to fabricate it for you!
Best of luck!