hedder/ intake difference in flange thickness??

I have a set of Hooker Supsr Comp Hedders and an 'Offy' 4bbl intake with a Holley 390 I would like to put on my slant. The intake flange is thicker than the hedder flange and will not mount up tight. I have talked to people and got advice on just putting 'shims' by the thinner hedder flange when mounting everything up and this should work. I question the durability as the car will be driven alot and I do not want to have to keep tweaking the bolts for leaks from the hedder and intake getting bounced around in the never ending Chicago potholes. I have also been told I can have the intake flange 'milled' down to the same thickness as the hedder flange but I am afraid it will cause the intake to crack ruining the whole deal. Since so many of you have this kind of setup what will work and not look 'cobbled' when everything is mounted? In addition to these questions would a dual 1bbl intake and carb setup with linkage be really difficult or overly expensive to obtain as I want something different on my car and think dual carbs with alot of detail would look pretty nice under the hood! Thanks for any help or info,
Chas.