I have a Lathemaster ZAY7045FG (very similar machine) and I just bought that exact same Leeson 2hp motor from http://www.electricmotorwarehouse.com which is the same seller in your Amazon link. I also bought a 3hp SJ200 from http://www.driveswarehouse.com Yes it is overkill for this application, both in terms of HP rating and being a sensorless vector VFD. A 2HP V/F would probably work just fine, but the difference in price is not all that much. I would rather buy a bigger and better drive in case I may want to use it for something else later.
I also find the SJ200's detachable control panel a must have. It makes mounting the drive much more flexible. A few other VFDs that have this feature too. I don't believe the L200 does.
Here's what you need to do to convert a D90 motor to fit:
1. Turn output shaft diameter down to 19mm
2. Cut new 6mm keyway (on opposite end of what's left of the old keyway)
3. Shorten the shaft length by 3mm
Shortening the shaft length is not all that critical. Based on my preliminary measurements, I told the machine shop not to shorten it at first. After I got the motor and trial fitted onto the mill, I found the mill has a dish shape at the bottom of the shaft "well", which kept the tip of the new motor shaft from going into completely. It was only about 1~2mm off. I just grinded a little bit off the shaft tip with an air cutoff wheel, and it fitted just fine.
Turning the shaft down to 19mm is no big deal if you have a good size lathe. Cutting the new keyway is also easy if you have a working mill and the right tool. Well, I have a brand new ZAY7045 mill and a brand new 8x14 lathe, but neither has been set up properly yet and both are taken apart for VFD retrofit. So it's the chicken or the egg thing... I suppose I could set them up first to machine the shaft, but the amount of work is just not worth it.
Anyhow, I had the same folks at electricmotorwarehouse.com do the machining - $100 per motor. It isn't cheap, but I get the motor and mod done all in one order, shipped to my door ready to install. I can get it done cheaper (maybe $40~50) at a local motor shop, I'm sure, but that will involve at least two trip to the shop. I'd like to think my time is worth at least $50. Not to mention the warranty issue for work done by 3rd party.
Here is the contact at electricmotorwarehouse, in case you choose to do the same as I did:
Winans Electric Motor Repair Inc.
Toll Free 1-877-986-6867
Monday thru Friday 7am to 4:30pm EST
Barry is very nice to work with and responds quickly to my emails. Tell him the guy in TX that just had two motors done sent ya.