I'm running a Curselax right now and I can confirm that it's an absolute beast. If you can get a couple Curses up, even fighting types don't really bother it all that much.
Speaking of dealing with fighting types, I've got a bit of a problem with that at the moment. My team has a bit of a weakness to both fighting types and Scarf mons (especially since those are mostly one in the same - I'm looking at you, Mienshao), and I'm currently running a defensive core of Forretress+Florges. However, bringing either of them in absolutely kills any offensive momentum I've built up, and their lack of ability to really threaten anything offensively makes things difficult for the rest of my team (offensive SR Nidoqueen, Mega Pidgeot, RP Tyrantrum, and the aforementioned Curselax). I was initially running Crobat, but that went too far in the other direction, as it usually ended up dying from too many repeated hits before it could Roost and not giving me the defensive support I needed. Could Doublade work as an acceptable alternative? It's typing lends itself well to countering fighting types, even though it fears Knock Off, and it should still be able to provide an acceptable amount of offensive pressure on both ends of the spectrum.