Before you abondon all hope....
I used to think that projects like this were worthless until.... I came across a set up where a guy mounted the blower on the right hand side of the engine bay and fixed it there with a custom bracket. Then he plumbed the blower outlet to an intake where normally the throttle body would reside (in other words: the roots blower was mounted remotely, like a centrifugal as opposed to directly to the top of the motor). He'd fabricated a small box for the blower discharge and another for the intake and welded 3 (or maybe 3 1/2) inch tubing between the two. Then it was just a matter of running the throttle linkage over to whatever throttle body you happen to use on the blower inlet. It was an appraoch that I'd never considered before. It also got me thinking about how easy it would have been to toss an air to air intercooler into the mix. The beauty is that you can use any intake you desire and still have the all the properties and instant throttle response of a positive displacement blower. If you wanted to, you could even loose the upper plenum alltogether and fab up a box that mates directly to the lower. One of these days I'll sit down and figure out if there's any thermal advantage to having it plumbed into a larger upper plenum where the blower discharge air has a little room to expand and loose some of that heat energy.
Just some stuff that made go "Hmmmmmm".