I just ordered a custom two core aluminum (two 1" cores) without oil cooler radiator from www.alumrad.com
for $475. He's built a few for D90 owners recently (with and without 7 baffle oil coolers), the pics and specs he e-mailed over are very nice. I should have mine any day now and will post pics. I'm doing the Mocal mod with remote oil cooler at the same time along with an oil pump rebuild and cleaning the oil pan. Look around for a builder, seems to be the better option on the radiator swap.