I don't know of any other than Terry saddler. Talk to him and get the WHOLE story from the get go to where he is now. Se my post on my page for the difference between the vw and the rotax. This is just the high points.

Hi Ray and welcome to the club. I have done extensive testing with the vw on the 701. I have a blog where you can go read about it. there are pictures and temps, all sorts of info there. I must say if you want any kind of reliability and peace of mind the cht MUST stay below 300 with the sensor under the head stud by the exhaust port. The others say 450 is acceptable because they have no choice. just read the blog and I'll be happy to answer any questions from there. As for the redrive I was a little disappointed. any kind of reliability there will require the heavy flywheel and a two blade wood prop. I used a light flywheel and three blade composite prop and fought it constantly. Remember, you are buying and they are selling, they are going to tell you what you WANT to hear. My opinion of " no trouble" and theirs is completely different. Talk to Terry Sadler, he is on the group here. Ask him for the WHOLE story from beginning to end.
Having said all that, I must tell you I have abandoned the vw and installed the rotax. The airworthiness certificate was handed to me today. The crankcase on the vw cracked at 148 hours when I was on the way to Oshkosh where I was scheduled to fly it in the Monday airshow. I never made it. The crack was in an area that let oil spew from a oil gallery off the pump. I almost lost the plane, had 1.5 quarts of oil left when I got it down with the whole engine compartment soaked. I could smell it on the exhaust, how it kept from catching fire is a mystery.
I used a cowling of my own design. I still have it and the mount if you are interested. Cheap.
Do a google search for Wayne's experiments and read up. Keep in touch.
wayne
Keep in tou