I have the N3DS and O3DS AGB_FIRM's. Ive installed them with devmenu and fbi. I posted them awhile ago on a that "iso site". They are pretty safe to install and you cant brick your 3ds from a modded AGB_firm because it was later on in the 3ds firmwares i believe. Would you like the N3DS one?
Thanks, i have them both. I daily keep an eye on the iso site for anything new. But i prefer the gba option given on a cfw because i heard of any changes on sysnand my affect later system upgrades/downgrades or A9LH proccess. I do not know what is true but i prefer all my changes on emunand