One aspect to consider if you already have a need for a third spool to control a top and tilt for example, is to buy a loader valve with 3 spools or 4 spools.
Cross hydraulics have been a big help to to other owners either with problems or needing advice on getting the features they want in a loader valve.
This spec sheet shows, with a simple 2 spool loader valve, how many different ways it can be spec'd to best suit your tractor and your needs.
A joystick is easily added to a valve with two levers. It does not change what feature is in each spool.
https://crossmfg.com/
Jeff, one of their Tech guys, is easily reached by phone and can guide you through issues such as having regen on the bucket part of the loader valve.
The reason I am suggesting some home work now is since you already know you want more than just a loader control is because another hydraulic device it can bring you into the world of power beyond which has confused many. It would also need to be ordered as a option on the loader valve. It usually is a plug which screws into the valve body.
You talk of reusing your existing FEL valve but do you know what features it has, regen perhaps, a detent? Does it have power beyond to feed the rear 3 pt hitch since it presently is being supplied with an independent front mounted pump and the 3 pt works off the main hydraulic pump. Not likely it has PB.
I do not know but perhaps CROSS can supply a 3 spool loader valve with a joystick for the two spools used for the loader and a third lever for the top and tilt.
BUCHER hydraulics has and may still be a supplier of loader valves companies like Kubota buy to install on new tractors. When owners of older Kubota's went to BUCHER for advice, since there was a BUCHER metal tag on their loader along with a model number, they were told they would have to go back to Kubota for any parts or advice as it was an OEM valve.
https://www.bucherhydraulics.com/30971/start/start.aspx
As you see on the CROSS sheet hydraulic valves have flow ratings, 10 gpm, 15 gpm...... It is natural to think bigger is better.
No.
With a valve with too high a flow rating, you loose the ability to finely control movement of your FEL or other.
Carefully select the valves and valve features you need and be happy forever, grab a generic FEL valve a Harbor Freight or similar and you may end up with a life time of frustration.
Dave