M.McMillian, I have a 5400 with a 1001 Kubota loader that I bought Dec '99. When it was time to buy I came across a used 4700, 5400, and 6800, all with less than 100 hours. I got the best deal with the 5400, but really wanted the 6800. You won't go wrong with it.
As to your loader questions, I ran into a similar question. I was trying to decide between the Kubota and Bush Hog loader. I have not heard of a Quickie loader. Anyway, the Bush Hog loader was about $500 less expensive and would lift more. But about everyone I talked to told me to get the Kubota loader for the following reasons: Better fit on the tractor, better resale, the controls (lift and tilt) worked better, and it would hold up great.
Someone on this board has a 4700, a Bush Hog loader, and lives in Montanna or Wyoming. I can't remember his name off the top of my head. He helped me a lot when I was trying to decided which model to buy. He loved his loader and had had no problems with it. I think his only complaint was that his Kubota was a 2x2 instead of a 4x4.
As I said, I have a Kubota loader and have never had one problem with it. I am really happy with how it performs. I do recommend you get a heavy duty tooth bar on the loader. When I am pushing over trees, digging up a mound, or push brush to the burn pile it makes the job much easier. My tooth bar removes with two big bolts and takes about 4 minutes.
Mr. Carver is great. He help me when I was trying to decide what to buy. You won't go wrong with him.