rich - the problem with a recommendation is that few people have any experience beyond of their own machine.
I have a Woodviking Biotriplex and Ulma burner. If you search over the last 18 months or so for me and pellets you should find plenty of posts about it and pics.
If you want to find out more about woodviking, I recommend speaking to Mike Thorne at http://www.ecogreenenergy.co.uk/About-eco-green-energy-devon.aspx and he's in the SW
He has been helpful to me in the past even though I did not get my boiler through him.
My neighbour has a bells and whistles OkoFEN http://www.oekofen.co.uk/ which cost probably 3 times as much as mine, but it's very advanced. Mines a bit more hands on. But Ive started burning logs in mine daily and saving a ton of money in the process. In comparison with oil, my pellets are about 5-10% cheaper. Burning firewood that I can get cheap, is probably less than 30% of the price of oil.
You'll rarely find an installer that knows more than one manufacturer so there's little help researching out there. You just have to do the leg work yourself.
feel free to ask any qus in here or at my PM.