Epson Stylus Pro 4000 RIP software (New to large format printing)

HI,

I am new to printing with a large format printer, i have managed to pick up an epson pro 4000 for a very good price i haven't picked it up yet and i will be picking it up later in the week. I'm looking to use it for A3 and A2 giclee fine art prints, these prints need to be very good quality, i have OEM inks for it and good quality fine art paper. I have a few questions though, I've read a lot about RIP software, how important is this and has anyone got a suggestion on good RIP software to go with this print and a mac running OSX 10.7 ?

Is there anything else i need for using this printer for giclee fine art prints ?

Any help would be appreciated