The Digi 001 is a nice system and has 18 inputs, so you can actually record 18 tracks simutaneously. But you have to be carefull, because you will need a lot of extra equipment to use all the input. And it is not necessarily cheap, especially for really nice sound.
Inputs 1-2 have a pre-amp wired directly to the digital converts. So you can plug a mic (XLR or 1/4 balanced) directly into the breakout box. These two channels also have phantom power.
Inputs 3-8 are 1/4" balanced and have no preamp, so you need a mixer with preamps if you want to use them with a mic to record. The converters are good, but not top-of-the-line equipment. You can plug your synths directly into these inputs with no problems.
Inputs 9-16 are an just an Adat optical input and output "ports" on the soundcard, not the breakout box. So you need to buy an interface if you want to use them for mic inputs to record. The Digimax or RME will give you 8 nice preamps and converters for this ADAT "port", but will run you about $1200. Alesis also makes an Adat interface for around $350, then you can use the preamps in you mixer and connect directly.
Inputs 17-18 are S/PDIF and on the back of the breakout box, so you will need both a pre-amp/converter setup to use this for recording.
It is a nice system and pretty flexible. There is a lot of room to grow. You should be able to get the Digi 001 for about $750, and that includes ProTools LE, which maxes out at 24 tracks. If you need more tracks, you can buy Logic and run it with the Digi.
