I want to add some extra hydralics on my tractor, either two or three spools .. what is the simpliest way.. I already have a loader, what is a power beyond kit, and how much $ are they ?
If you search on Power Beyond you will find lots of information. My non technical description is that if your loader control has power beyond, there is basically a port that you can tap off to take the hydraulics "beyond" to another control (can be in the rear) and set of valves. My guess is that your loader valve does have power beyond so you will need to decide how many remotes you want on the rear, buy a valve and pipe it in. I did mine last year and I found it to be relatively easy BUT, figuring out all the fittings takes a lot of time.
Here is a link to a thread that includes pics of my install - there are other similar threads out there. Search on Rear Remotes and you will find lots of information. Search this forum and the customization forum since there was not always a separate hydraulic forum.
Factory stuff is usually nice but for the L2800/L3400 Kubota has a generic set of remotes that bolt on to the ROPS. An aftermarket setup using the Prince SV valves that MadRef points to in the threads above is not much different and about 1/3 the cost.