the easiest way to add a remote is to buy one of the valves that bolts right to the hyd cover in place of the 3x5 option cover. they come in sangle and dual spool, and many are switchable from DA to SA.
price runs from 150-450$ for single to dual spool used.. and about twice that for new.
another option is to get a power beyond plate and sandwich it unde rthe 3x5 cover. it will have in / out ports to plumb in another valve.
that palte and an oring kit should cost you less than 130$ shipped. lets you use a generic OC valve.
another option is to install a diverter valve on the top cover. it is a push / pull affair that sells for about 100$ used.. and has a port on it. you feed that port to the input side of your OC valve and plumb it's return to the tank via a fitting you can install in the fill cap. pull onthe diverter to kill the 3pt and run the remote.
lastly.. the cheap way is similar to above... take a loop of chain and chain under the axle trumpet and up thru the knuckle ont he 3pt so that the upper lift arms are chained to the axle. take the plug out of the 3x5 cover and run that to your OC valve. plumb return to sump as above.
you loose 3pt.. but cost is a piece of chain... unchain when done with remote and use 3pt as needed.