Hi,
I use the Ricoh3110 which is absolutely fine for good quality A4 sublimation. I'm using cheap ebay ink at the moment which gives surprisingly good results but I'm pretty sure it won't wash well! I'll probably switch to Sawgrass once I'm through the testing stage. The mugs I have done have faded (but only very, very slightly after 2 weeks solidly in the dishwasher!).
There are some good value starter packs and you get 10% off with Listawood.
The problem I've had initially with the mugs is the bottom of the image faded. This seems to be a common problem as the base takes longer to heat and so to sublimate. Some seem to have different methods of warming the base but as I say, I just out the idle temp lower and it has solved it for me. It may be the mug but as I get good results from my method now I'm going to stick with the mugs and what I'm doing.
Good luck with everything.