Tim W,
the IAF operated the following variants of the Mirage (other than the Kfir)
IIIC : converting the revell kit (which is basically a IIIE) is quite involved, as you will have to change the tail section (the engine had a different exhaust, which was longer and smaller in diameter), remove the ventral bulge and replacing it with a smaller one with a strake. The instrument panel would be different too.
Nesher/Dagger : was an unauthorized copy of the french Mirage 5 (equipped with a smaller navigation radar in a pointed nose). You can obtain the Nesher by using the older Revell Mirage 5 kit, that includes that nose option. If you have the recently reissued box (the same that I have), you could obtain the M5 nose by extensively reworking the recon nose of the IIIR, or vacuum forming a new one.
For the kfir there's a conversion set issued by CAM, but I think one can convert it from scratch, with a lot of work
Cheers