You shouldn't need any "jumbo" wrenches for the tractors you have.
Everything is meteric, but I'd also suggest a set of standards. If I am not mistaken I think the hydraulic hoses are still SAE sizes. So if you ever need a replaceent you may need standards.
I'd start with a set of 3/8 and 1/2 drive standard AND meteric sockets.
And also a set of std and met. wrenches.
Most kits come with an assortment of extensions, u-joints, etc.
For sockets, dont mess with 12-point, get the 6 pointers unless you are doing engine rebuilds because about the only thing 12 point on anything automotive/tractors is flywheel bolts, rod cap bolts, and somethimes head bolts.
But for the wrenches I perfer 12 point. 6-point is a PITA especally in close quarters.
I can personally vouch for the quality of the HF pittsburgh brand deep impact sockets. I havent broke a one yet and I use them in an IR 2135TI Impact that has no trouble snapping new 1/2" gr8 bolts.
Aside from them basic sockets and wrenches, you will need a few screwdrivers for miscellaneous hose clamps and small prying jobs.
If you havent got one, get a big 15" crescent wrench. They are good for things like tightening the nut on a tow ball and such.
And a couple of specialty tools you may want to consider while you are there is a greese gun for sure and an oil filter wrench.
And vice grips and pliers are also handy to have with you on the tractor as well as a crescent for things like the turnbuckels on the 3PH.
PS, you can never have too many tools. I am also one who has $1000's invested. The basic stuff you need isn't going to break the bank. It when you get into all the specalty things like DVOM's, flaring tools, ball joint seperators, dial indicators, cam R&R tools, bearing drivers, pullers, enging rebuild tools, etc. etc. But you should be able to get the things I listed and come in well under the $400 mark at HF.