my own .oooo2 cents actually running a turbo in my car
first off you could go do it yourself fuel injection to give you better performance
try
www.msefi.com
intercooling is easy to do for your size i would look on ebay for like a used one
the vw corrado has a fairly small unit that would work well
since your racing in cold weather i would not worry about the extra weight and complication of water to air intrcooling
a properly sized air to air intercooler will/should work just fine