I have pretty much given up jigging for Doggies but used to quite often.
On the assists I would advise against wire. The whole theory of an assist hook is that it hangs loosely and moves easily into the fish mouth when it opens and a vacuum, suction effect is created. Wire is just too stiff and I think you will find you keep missing hookups. If you must have a metal assist, then chain linked split rings are more effective than wire in my experience, but still not great.
I used to stick mostly to kevlar and just accept that sometimes you will lose a fish due to the cord being bitten through. You will definitely find you get better hookups with kevlar assists. You have to balance that against the less efficient but bite-resistant metal options.
On jig types, I have caught baby Doggies on massive 700 gram spears and large Doggies on little 300 gram centre weights. As with any jigging, the optimum jig type depends a lot on the mood of the fish, but Doggies are notably not very fussy in my experience.
