Best Flash Cartridge for beginners?

Hey, sorry if I'm posting this in the wrong board.

I've seen G6DS, R4DS, M3, and etc.

And I just want to know which is the best for a beginner? I've heard good things about the R4DS, as it can support linux(?) and more.

I was wondering if someone could help me get into the groove of it all, because I really want to start making some homebrews and/or playing some ^^.

Basically, if anyone can post a list of what I need to get started so I can play some homebrews, and a good link to a site with tuts on this kind of thing, thanks.

EDIT:**

I guess the real question is... what's the difference between 1-slot devices and 2-slot devices?

And which is better, R4 or M3? or what's the difference between them?

And do any of these have gba/snes/nes support?

And is there a working version of linux for either of these?

Sorry if my questions seem untelligable, but I honestly have no idea where to start.

I basically want homebrews, and nes/snes/gba/gbc support, and linux if possible.

^^ hope this isn't too much to ask, thanks again.

r4ds is the easiest,anything you should worry about,now r4 team has released the new shell r4ds,have found Digimartz.com has the new r4ds.

r4 and m3 simply are basically the same.
so id go with either