Allan~
I have been very happy with the Sail Rite machine I bought as a birthday present to myself several (10?) years ago. Although I had used a Sears Kenmore (with the appropriate needles and threads) for many years, the big difference with a real canvas machine is the upper and lower feed dogs. The Kenmore had only lower dogs. Having both really grabs several layers of thick canvas (cotton duck, Sunbrella, Cordura) and pulls them beneath the needle in a very positive and measured way. I think that is what they call a "walking foot"....
I bought the Ultrafeed LSZ. I see current prices are twice what I paid - and I bought one without a case as I knew it would be stored in a drawer beneath my "assembly bench". I do not see that option on their site now.
Hope this helps!
SJS