Based on experience: if you need standby power often enough to consider a PTO-driven generator you shouldn't. Get a good quality pad-mount standby, use a proper whole-house transfer switch, and rig the system to run on natural gas or propane. Stay away from those dinky 6-circuit boxes that come with some units (your life will be easier, trust me); you'll get a better overall install and be happier over time.
Save the tractor to be available for snow and debris removal.
Biggest problem I see in our installs in storm-prone midcontinent area is fuel management. Our little 12-KW Lincoln secondary standby uses about a gallon an hour at full output. Where are you going to store that much gasoline safely and prevent it from becoming stale over time? If you power is out, so is the service station down the road. If you find a station open, how much time will you allocate to standing in line, pay cash, and transport a sufficient quantity back to the house. I've seen fights break out in fuel lines. Bad place to be in times of stress.
I'm reluctant to offer specifics due to liability but a thought you may consider: gasoline mixed with various retail admixtures can be stored under pressure in an ASTM-rated pressure cylinder and remain 'good' for up to three years. That's the extent of my ongoing proving thus far. Pressurizing agent would be propane, never air. There are inherent life-safety hazards in this process and you should be aware of what you are doing. City dwellers might have a bit of a problem with fire/codes enforcement if discovered.
If not a hardwired pad-mount unit, get a capable name-brand engine-driven welding generator with sufficienct aux power to fit your needs. Get all you can afford and then buy more. You can't go wrong. And you can get your money back someday on resell if you choose. Rig it to run on propane either when bought new by OEM or aftermarket via conversion kit. Put it on a trailer and use a 20-pound bbq bottle to run it for chores.
When power drops use an AGA-approved quick-connect to hook it to existing larger propane tank set near transfer switch. You can even reload your small bottle yourself if inclined and if your large tank has a liquid outlet valve.
Very few installs we do in rural area have access to natgas. You can use conversion kits to run dual-fuel gasoline / natgas. Great source is CarbTurbo.Com.
Install a 50-amp 4-prong weatherproof-in-use receptacle at your whole-house transfer switch. Pull the welding tailer up to pole, flip the transfer switch, quick-connect fuel supply from large tank to welder, plug the double-male jumper into the machine then into the transfer switch, start machine, let warm up, flip transfer switch to aux position, go inside be happy.
Stock expendables for welder onsite at all times: oil and fuel filters (even if propane, especially if propane as is relatively dirty fuel), plugs, air filter, whatever you might need.
The longest we've been down was 17.5-days; twice in ten years 14-days. Multiple outages in winter icestorms, summer peak heat overload brownouts, spring wind and lightning storms and the occasional brushfire takes down lines. Fun times.
We've learned: a 45-KW Onan prime-rated propane with 1,200-gals as primary and a 12-KW Lincoln on gas/propane as secondary keeps us lit. And a WinPower PTO unit for field work and for third-tier standby if absolutely required.
Good luck, mi amigo.