The boots are used since they offer a wider range of movement, in the commercial use at least. What kind of bellow were you thinking of using? It's been our experience that bellows pipe like this:
http://www.grpipes.com/catalogs/GrandRock2015v2i1.pdf (pg90 on the PDF)
Have a very limited range, and it's only in 1 direction really. Bellows like this will break when it exceeds that range of motion. I think it's been documented here the lengths we offer are 3 degree of movement. I would have to double check that for sure.
The shorter the bellow, the less range it has obviously. I suppose knowing how much this stuff will move while it's under power would tell you the best set up to use?
Just my $.02
