Yeah, Divineo is where I purchased my neo max system (haven't heard anything negative about them)
As Roger said, it depends on how much money you are willing to invest.. You have a 1 gigabit cart, which is compatible with the current mk2/mk3 technology (and is presently the only way to run 1 gig commercial roms at full speed using neoflash products). Buying a separate mk2/mk3 unit will give you access to the latest menu software...
If you want to return the neoflash linker set, there are numerous options:
There is a less expensive NeoMax kit (using the latest mk3 technology -- the main drawback here is the cart is only 512 Mb, and the mk3 itself has only 128 Mb internal flash space -- not very useful, considering most commercial roms are over 128 Mb.)
If you want another less expensive alternative, there is mk3 2006 as Roger said (using a neokey and a mk3 512). The main problem here is that the neo-key isn't an ideal substitute for a regular flashcart.. A neo-key can't hold much at all, and you can't play gba roms on your ds with a neo-key only (i.e. you need a regular flashcart)
Finally, for other non-neoflash products, there are viable alternatives to neoflash (supercard being very good value and m3 as well). If you want to run roms, these products are very good at that, with high compatibilty levels as well...
BruceG