That was a very good kit a very long time ago, but you can now buy a decent new twin head kit for just a little more than they asking price, and frankly you should.
1. Only full and half power settings (from memory) on the 400D
2. You may struggle to get any repairs done
3. You may struggle to get modelling bulbs for it
4. There are absolutely no modifiers available for it, so if you want any accessories other than what's provided, you won't get them.
I'm not saying don't buy it, but personally I wouldn't pay more than half that amount for it.