Answer: NO
Been there, tried that. Maybe something in the $15K+ range has come about recently that is truly properly designed, but nothing I have ever heard up to about $10K can do what you want as a pre/pro.
Not only is there no HT pre/pro that I have ever heard but there is not 5 or 7 channel amp either that is going to compete with a 2-channel based system (of comparable quality) when it comes to 2-channel performance.
Save yourself the time, frustration and ultimately the cost and stick with your 2-channel rig incorporating the HT passthrough on your preamp.
Oh, and don't forget when you buy a new Pre/Pro you can expect it to drop in value by about 80-90% in just a few years! Just get a used HT receiver that is about 2 years old, you'll pay about 25 cents on the dollar. I got my Pioneer Elite with TrueHD and all sorts of other junk, including HDMI switching, second zone, Ipod in and all that other stuff for $185 (it was 14 months since new release when I bought it) on a product that listed for over $1,000.