Changing Internal Wastegate

[ZeroG]

Hey I have a problem Ive been wrestling with by myself for a couple of weeks now and Im stumped. I have turbo with an internal wastegate of 16 psi (according to the person I bought it from) and I wanted to run about 6-8 psi b\c thats what someone told me would be best. I have a 92 honda civic hb, a fmu thats like a 6 or 9 to one ratio, an intercooler blow off valve the normal stuff you need for a turbo setup. The manifold doesnt have a port for an external waste gate. What would be the best thing to do, would I be able to get a boost controller and wire it to the wastegate actuator somehow and set it that way or would I have to weld an external wastegate on the manifold to get the boost I want.
Ive never heard of an way to down the boost just up it.
Also someone told me when you use a intercooler you loose a lot of boost. Would the the boost drop to 6- 8 psi or would it even drop at all.
Thanxs for any help you guys can give me on this.
Oh and the turbos a td04 its some gen 1 turbo.