Intercoolers aren't always necessary. I don't think you would have to have one if you were running 6 psi. You could just run your pipe where an intercooler would go and that could help to cool the air some.
Cooler air is always better so maybe you could look into some cheap small intercoolers. If you have some skills with a welder or know someone that does, you could make your own intercooler.
I don't know if any turbo cars came stock with intercoolers but if they did you might could find something at a junk yard.