Best eyepieces for fast Newt?

Guys. I have a 12" F4 Newt and my cheap eyepieces are not cutting it, although they were ok in my 8" F6. I'll be replacing them soon and any input from experienced observers would be welcome. I'm thinking Lanthanums, Naglers, Radians etc. Obviously an eyepiece has a tough job in coping with an F4 system so I don't want to buy several expensive EPs to find they're not doing it. Btw, I've got a baader MPCC so that will help