I have a Nintendo DSi XL (I like the bigger screens) and having heard about Flash Carts like the SuperCardDSTWO that let you put homebrew and DS game ROMs onto micro SD cards and load them into the DS thought it would be really cool to get one so that I can experience lots of great DS and homebrew titles I might have missed and have an instant game collection ready to play without swapping cartridges. Whilst I like the possibility of Gameboy Advance and SNES emulation the SuperCardDSTWO is said to have, these are not essential and I would be willing to do without them if another device does the core DS ROM loading just as well and is significantly cheaper? (cost is an issue).
Anyway bearing that in mind, what is the best Flash Cart system for DS that would meet my needs?
Also 3DS compatibility would be nice in case I upgrade at a later date (I don't expect it to play 3DS games, of course).
Secondly, as I live in the UK I would like to use a UK based supplier and of course any international supplier would need to ship to the UK. So considering my location what is the best reputable supplier for a DS Flash Cart?