I have just put together a new PC from scratch. So I have been doing a bit of research on what to get. I have been aiming for cheap, fast, and quiet and I have ended up with a nice Core i5 3570K with 16 GB RAM. If you are looking to buy a new PC, you can see the part-list and read more about my new DAW PC here.
Looks good, I think the i5-3570K is the sweet spot of price v performance at the moment.
The one thing I would have added is an SSD system drive (as well as the large storage drive). Probably one of the Corsair, either the Performance if cost isn’t an object, or GT for a more realistic budget.
Well, actually I have a SSD cache drive from my old setup. It really helps to speed things up: Ableton startup, loading Live sets etc. I gives less disk I/O reads, and I think that also helps Ableton performing better. I might go for a normal SSD drive next time, but for now the cache drive is performing really well.
Would this type of setup be enough for 30-40 channel tracks with plugins in it, without bouncing things to audio?
Yes. I’m currently working on a tune with 43 tracks + 3 return tracks. The CPU-meter is hitting 30-35 on average. But of course it is also important what plugins you use. I should also mention that it is not playing all 43 tracks at the same time 
That is awesome man, yeah ofcourse they won’t be playing at the same time but plug-ins are like Waves SSL, O-zone etc.