If you can add remotes in factory location, I'd go that route. I'm not sure if your tractor has the provisions or the parts available to add rear remotes, I would think it would, but I don't know.
What you are thinking, may be the best way for your tractor. Hopefully OldHokie will chime back in, he's good with hydraulics.
Ding, dong
Kubota seems to have gone out of their way to make the remote kits for the standard L hard to find. They are in the whole goods catalogs but are not listed in the Options tabs on KPAD like all of the other favored models. WTF!!!
Anyway the "factory" valve kits are very nicely integrated but IMO the remote outlets are pretty chintzy. The base kit for the L3200 is/was L7334 and it installs just like the kits for the current L01's - picture of the L3200 kit below. Messicks has online pricing (use that whole goods number) for the individual pieces and a single remote would run you about $1k if purchased ala carte. That would not include the hoses or outlets.
There has been a lot of speculation that the current L01 kits (L7211B) may work on the older models but I have not seen any confirmation of that. You could get the entire L01 base kit and first valve for about the same price.
As Matt knows I have been working on my own solution which would be less expensive, equally well integrated, and IMO less chintzy. It is very close but still incomplete and I don't expect to get back to it until the fall.
Dan