Do you already have the computer and how essential is it for other things ?

If you already have a G4 cube Id say it is nice.

However, the mini-mac is a cheap and very powerful big bang for your buck computer which will ship with garage band 2 installed on it.

Garage band is a bare bonus program and should not be compared with ProTools as it is in another world however if the bare bones are what you want it may be all you need and it will happily run a bunch of midi stuff. It interfaces with iTunes to export material as an mp3 etc. You may also want to have a look at Logic LE (~300 off the shelf or 200 bundled) or even Logic Pro (Im using logic pro at the moment, and it comes in at a cool grand). Logic is not the most intuitive interface but is very comprehensive and comes with many different plugins from pitch correctors to compressors to EQs.

There are a million audio interfaces (thing that you plug instruments etc into which will then digitized the signal and send it off to the computer where it can be processed and written to the disk) on the market and the exact spec of what you want to do will determine which one is or you.

If you need multi-channel simultaneous in / Out (I/O). Id have a look at the MOTU 828 mk II fire wire interface (up to 20 simultaneous I/O). It comes with a bunch of whistles and bells and free multitrack recording software (audio desk). If you go with the Mac Cube you will probably want some sort of firewire I/O even if it only allows two channel simultaneous recording.

Or you could look a the all in ones. I have owned both the D1200 and a D1600 and can recommend both. They are very nice machines. The pres are a little week however with a little tweaking it is posable to find the sweet spot ! In terms of computer editing you have to export either:

individual tracks to a computer for editing in the program of your choice

or

mix and master using the unit and export as either a CD (wav files which play like a regular CD) or to a computer via USB for MP3 encoding).

Unlike the Rolland VS systems they don't have a mouse / monitor port. Unlike the Rollands the Korgs don't use any form of data compression when writing to the disk. Many people will tell you that this means that the Korgs sound nicer.

Have a look at some of the material by a dude known as Gospelsinger (Tommy) over at www.Korgstudios.com. He uses nothing but a D1600 and has had some very nice results (and an endorsement from Carvin !!).

Best of luck

Simon