Does your vinyl cutter have registration mark sensors? You won't be able to contour cut inkjet transfers without that feature on your plotter.
A popular printer for transfers here is the Epson C88+, which I believe is called the D88 in the UK. They're available as refurbs at Epson for really cheap. The thing is, they're limited to A4 or 8.5x11 prints. I don't know of a larger printer in the UK to use, but if I were to buy one here in the US, it would be either the 1400 or 1800. Both of those can do 13x19 prints, but the 1400 uses the wrong inks, so I'd need to get a continuous ink system for it that uses pigment inks.
That's the main thing...get a printer (or continuous ink system) that uses PIGMENT inks, NOT DYE inks.
For transfer paper for lights, I HIGHLY recommend Jet-Pro SofStretch, but I'm not sure if it's available in the UK yet or not. It's very soft after it's been washed, and it holds color very well adn it doesn't crack.
Good luck!
