There's only one I know of & that's Company B's UHU add-on. It's more suited to sticking on a 251 or possibly a truck, but both the smaller IR light & scope might fit onto tank cupolas. (Warlord also do a Panther G with IR gear, but you can't get the lights/scopes seperately.)
That said, they don't make for terribly difficult scratchbuilds, you just nedd a selection of plastic tube of the sort available in most art shops, good hunting!