Pirate Ork Heads from MAXMINI:
Razig weapons packs from Reaper Miniatures:
For heavy weapons, the Imperial Arquebus from Freebooter Miniatures:
...and, even though I just cast a hundred or so custom bases specifically for my Orks, I think I'm gonna have to go with the fantastic-looking "Shiver Me Timbers" bases from Iron Halo:
There's going to be a lot of other custom bits as well - stay tuned!