Well dude... I used to have an R4, but to be honest, R4 is the "old stock" now. The same people who make R4 also make M3 (and the models are practically the same, different labels, not sure why).
The newest one though from them is the M3 Real. You can find it here:http://www.kickgaming.com/simply-real-c-27.html?filter_id=9
Wait... they're out of stock.... oh well... But yeah, what you're looking for is the M3 Real. The Perfect bundle also allows compatibility with GBA games and homebrew.
I can also attest to Kickgaming that I've had pretty good service from them. No problems, ever... And it comes from Canada, so I don't have to pay tax. But yeah, check the site, they'll probably get more M3 Reals in stock in a week or two if you don't want to test your luck with other services.
Best luck man.
Oh... if you're really a picky buyer, you might also want to consider the CycloDS, it's probably the other "Best" cart out there.