Throw out a price and I'm sure you could get any number of better suggestions than Blaupunkt. Some of their head units are okay, but I'm not overly impressed by most of their other stuff.
What impedence load are you looking to have the 400W at?
Hifonics NX400 is a nice amp. It gives 400x1 at 4ohms and 200x2 at 2ohms.