Yea like everyone else said, just get RE:UC, Ghost Squad and HOTD. Oh yea, that WiiWare Western shooter game is also fun. Me and my girl are the same way, we love out shooters.
As much as I love the gun add-ons, the only one I tried it for and liked it was Ghost Squad, I did try RE but the lag between the wiimote and the onscreen cursor was just to bad for me, I'm way better with just the wiimote. Have'nt tried it with HOTD tho.