GBALDR is probably your best bet, you use it with a slot 1 cart.
Magic of search engine is in my control! kazaam. http://gbatemp.net/index.php?download=445
http://wiki.gbatemp.net/index.php?title=3_..._for_EZ-Flash_V
You can also use the 3 in 1 to dump NDS games. Very versatile product I must say!
slow shipping --> http://www.dealextreme.com/details.dx/sku.2967
faster --> http://www.gameyeeeah.com/ezflash-in-expan...lack-p-217.html (use code GBATEMP to get discount at checkout)
fast! but expensive --> http://www.realhotstuff.com/expansion-pack-p-194.html (code: RHS07 for 5% discount)
Alright, this is good.
One final question: The dumper also dumped the GBA game's .sav, if I edit it with a trainer, is there a way I can restore it to the GBA carT?
Although I would suggest GBAldr WRG's take on the old DS rom dumper was supposed to have swap every two megs GBA dumping abilities. Not sure if they added SCSD or it was CF only though.