MAC- Digidesign Digi001 looks like the best deal!! If you're not happy with it's midi side than simply sync up your favourite sequencer and you're laughing!!!!

PC- Steinberg Studio Pack with Cubase VST, Wavelab and audio card with ADAI I/O etc. Looks really happening.

You can also use Logic Audio 4.2 and above with both these systems. With the Digi001, a good dedicated 2 track editor like Bias Peak or TC Spark wouldn't go amiss. The Steinberg producer pack already comes with Wavelab 2.0 for 2 track editing and CD burning but I strongly suggest spending the extra and upgrading it to 3.0!!

All the very best! Korgasm.