most of the one-wire alternators don't charge at low speeds. So typically on vehicles that are using them (since I'm more familiar with one-wire kits on vehicles than tractors), you get in hit the key, let the motor start. Then, after you look at the volt gage, you see that it is still not charging, so you have to "blip" the throttle, which increases rpm, then it starts genning. Normally on the GM style 1-wire, it's about 1500 rpm give or take. There are also some Ford 3G style one-wire stuff that really isn't a dedicated one-wire, however it does only require one wire to work. Unfortunately you also have the issue of it constantly charging at high amperage rather than using the voltage sensing circuit which varies the output amperage.
For those reasons, the Denso style alterrator is your best bet if you must convert to an alternator. The original style generator works fine for 99% of users, and it's dirt simple, and very very easy to repair should the need arise. This doesn't account for broken lugs, etc of course--just the bearings because most of the time that's all that ever goes wrong.
With that said, when converting to Denso style, you will have to do some wiring changes and all the wiring you need will be at the voltage regulator EXCEPT the actual charge wire from the large lug on the back of the alternator. The charge wire needs to be upgraded according to the amperage output of the alternator; many are up around 40 to 50 amps, and we should assume that it will charge at 50A, so that's roughly going to be a 8ga wire. That wire goes directly to the battery or to the starter, and make sure to put a 75A fuse in that wire close to either the starter or battery so it doesn't short out and burn your tractor down.