This is the custom ROM i have been using for months now without any problem.
Follow the link to know about specifications of the RAM.
Feel free to flash ROMs in your android because 90% all soft bricks can be solved by Odin. Just make sure that the custom ROM is having the same baseband version like XXKPQ, KPE, KP9 etc. .
The above mentioned ROM is XXKPQ
So first flash Gingerbread XXKPQ ROM and then Poseidon’s ROM GB.XXKPQ
Follow the link
http://mobilehere.net/2011/12/samsung-poseidons-rom-gb-xxkpq-for-samsung-galaxy-gt-i9003.htmlHere is the torrent file which has following filesAmit Bagarias CF root final/CFROOT_GT-I9003_PDA-2011-12-01.tar 7.15MB
Odin3 v1.7.exe 412.50KB
Poseidon ROM/POSEIDON'S_ROM_RC1_XXKPQ[27.11.11].zip 180.47MB
Read me.pptx 39.34KB
Readme first/Download mode.mp4 5.69MB
Readme first/Flashing CF root.pptx 45.46KB
Readme first/Flashing Stock ROM using ODIN.pptx 42.46KB
Readme first/Installing Poseidon’s ROM.pptx 46.00KB
Readme first/POSEIDON screenshots.docx 5.02MB
Readme first/Read me.pptx 39.35KB
Readme first/Recovery Mode.mp4 14.47MB
Readme first/Thanks.docx 103.05KB
Stock ROM/GT-I9003_SER_I9003XXKPQ_I9003XXKPQ_I9003SERKPQ/I9003XXKPQ_I9003XXKPQ_I9003SERKPQ_HOME.tar.md5 340.96MB
Stock ROM/GT-I9003_SER_I9003XXKPQ_I9003XXKPQ_I9003SERKPQ/Odin3 v1.7.exe 412.50KB
Stock ROM/GT-I9003_SER_I9003XXKPQ_I9003XXKPQ_I9003SERKPQ/SS_DL.dll 269.50KB
Torrenthttp://beta.demonoid.me/files/details/2808488/