I personally would NOT use those pistons in a blown application. If you were talking 4 lbs of boost I would say go for it. Hyperutectic pistons are CAST pistons. If you do your research they DO NOT suggest running cast pistons in blown engines that are being built to make power. You said 10 or 11 lbs of boost. For a roots blower that is going to make a ton of torque and power. Don't confuse that boost with the boost of the turbo cars or centrif blowers. Roots blower will also make more heat and be more prone to detonation if things are not set-up correctly.
Cast pistons are good to maybe 5lbs of boost. You will no doubt break those pistons if you run boost on them.
Before you throw a blower on anything make sure you do lots of research. While it is possible to just slap a blower on an engine and it will make power, there is a right way and lots of wrong ways to do it. If you want to make power and want the engine to live do it right.
I have forged pistons and 8.47:1 compression I run 12lbs of boost on pump gas, that is REALLY pushing the limits on 91 octane. Make sure you check into what boost does to your "effective" compression ratio. If you need help finding this info let me know I will try to post some links. Actually go to www.blowerdriveservice.com
and browse the FAQ section, along with the rest of the site. That will not be all the info you need but, it will get you started in the right direction. I also HIGHLY suggest picking up (and reading) a book called "Street Supercharging" by SA Designs. Lots of good info in there to get you started.
Not trying to rain on your parade but, I would hate to see you throw money away.
Check out my site and you can see a little of what it took to build my engine http://community.webshots.com/user/camaroman7d
Hope that helps some.