Heads for the 318

I would think that your original plan with the 318 heads you have would work the best, how are machine shop prices there? do you have any good junk yards where you are? if you do you could try looking for a set of "302" heads part # 4323302 used on 318 engines from about 1985 before the magnum heads came out and build them with 1.60 and 1.88 valves