IF I were to get another PTO generator it would just be a 3pt type. I see no reason at all for a trailer for one.
Looks like you have a selection of high HP tractors to choose from so it may work well for you. I would suggest spending the bucks for an 1800 RPM unit if you can find one.
I tried a 3600 RPM unit a while back and my little JD had to be run wide open to make 60 hertz. My tractor was at the lowest rated HP to run it with but it would not make 60 hertz with no load at normal PTO speed. Had to run my engine at 3600 RPM to carry any kind of load and keep hertz in range. Between that and the noisy thing spewing oil out the vent I took it back.
One of my neighbors had one hooked to a 100HP JD that had some injector issues and he blew his tractor up running it. Another neighbor ran the same generator on his 50HP Kubota with no problems but after the power came back on they bought a whole hose LP unit. I could hear his tractor screaming from my place 100+ yards away.
I went another route and bought a military surplus diesel generator. I figured treated diesel will keep well enough and I use enough to keep it rotated. I added a couple of 55 gal drums to store extra fuel in. I ended up right at $2000 for the generator and parts to build a load bank and house connections. Just did my first monthly test and exercise and it ran like a dream under a full load. I put it under the shed behind my attached garage and I can't even hear it in the house with the TV on.