My belief has always been "if they won't make the model, why should i be penalized for converting?" I recently got a Harlan Versh from War Machines because its an awesome model that says "Hi. Im an Inquisitor" and the fact that theres only 3 currently produced models for an HQ that literally has thousands of ways to gear and no models for any of the gear? That said, most of my non GW stuff is mostly bits, but its mostly because its stuff that they simply won't make (like easy to get carapace armor) or stuff that simply does not exist (like half of the original DE line and most of the tyranid stuff!) Ive used non GW helmets and rifles for my Vespid/ Boba Fett Auxiliaries conversion, i have tons of maxi mini melta guns, roman "skirts" and head crests for my Ultras, and i use a mantic forge father canon for my Thunderfire because $50 for a tiny mini is too much. I plan on using Victoria miniatures to make a lovely cold one or motorcycle Praetorian rough riders, because current rough riders are lame and extremely overpriced.