You need either phat or slim version also check the model number at the back of your ps3 if it's downgrade able, I believe your ps3 is currently running on 4.55 update you need to downgrade it to 3.55 using e3 flasher or you can just check NGU people do downgrade services to ps3s for about £30, if you contact them they will probably put you on any cfw for an extra £10 max.
PS3 model number that can be downgraded to 3.55:
Fat models:
CECHH
CECHI
CECHJ
CECHK
CECHL
CECHM
CECHN
CECHO
CECHP
CECHQ
Slim models:
CECH- 20XXA
CECH- 20XXB
CECH- 21XXA
CECH- 21XXB
CECH- 25XXA*
CECH- 25XXB*
That's the cheapest thing you can do, or you can buy a ps3 that's already on any cfw, I bought mine for £120, also if you buy a jailbroken ps3 ask the seller if the console I'd is banned or not because if the console I'd is banned you need to spend another £30 to get a new console id so that you can get online.
Hope it helped