M3 Pro Mini SD

I was looking through the posts and I have a question. If I have a GB micro and all I want the m3 for is to play gba games which m3 should I buy? I was looking at the M3 Pro Mini SD on http://www.ubid.com//cgi-bin/div-us/search.html and I was wondering if that would work. The thing is it doesn't include the passkey or passcard but at http://gbatemp.net/index.php?showtopic=30243 it says "It can be used to play GBA games on the NDS without the Passkey/Passkey 2, or it can be used to play GBA games on any other GBA unit". Does that mean I don't need the passkey for the GBA or that only for the DS. One last question, it says it's compatible with all GBA software, max 32M. How will that restrict me exactly? Sorry if it seems like I didn't read anything but I have been and I'm kind of frustrated.

The Pro limits you to 4 MB of RAM, so no GBA binaries larger than that will load. This greatly limits its GBA usability. The M3 Perfect contains 32 MB of RAM and will run nearly all GBA binaries as a result.

Don't let them trick you with the "supports GBA games up to 32 Mbits" thing, as 32 Mb = 4 MB (notice the capitalization difference).