Cool!! If memory serves me correctly, the nose gear of the F/A-18 is twin wheel while that of the F/A-18L and F-17. Looking at Don Logan's book on the YF-17, I found centerline cutaways of the YF-17, F-17, and two-seat F-17. The production F-17 has a long, still pointed nose with a small radar. It looks like you could use either an AN/APG-66 with a different antenna from that on the F-16 or an AN/APG-67 as used on the F-20; I'd say to go with the AN/APG-67 as it did finally make it into production for the A-50 combat version of the T-50 trainer.
If you don't have Don Logan's book, I'll be glad to scan portions of it for you.