I can think of a few super nice neps to breed with rajah, of course not all are possible
Northiana, Veitchii Bario, Rafflesiana Giant, Lowii, Hamata, EP's Merriliana, Truncata 'King Of Spades' from BE, Truncata 'wide peristome' from EP.
If we cross campanulata, that'll be interesting. Or clipeata? Or eymae? I wonder if crossed with ampullaria, do we get a super large ampullaria?
