Cart. match for Sonic Frontiers SFP-1 Signature

Hello to all, Just picked up SFP-1 sig phono pre and Would like oppions on cartidge match. Phono pre can handle MM/MC (37 db gain MM) (57 db gain MC) Right now I currently have Blue Point Special 2.5mV and I have pre in MM, but it seems not to have enough gain, I can switch to MC but the pre is then out of phase and the Sonic Frontiers instruction manual says to switch + and - wires at cart to put back in phase, is this the best way or should I upgrade cart and if so what type should I be looking at? Thanks!