Always happy to help out the elderly when I can! If you were showing at Western Subs on Tuesday and won the Inter section, you would win a pair of mine - Double Factor cock and Spangle Grey Green hen. The hen is closely related to the cock you purchased! I have bred a few spangles this year so should be able to find something for you next year when the youngsters moult out.
As for the seed, the seed we use is MaxiSeed from Max Douglas of Murrami (Leeton). I have used this seed since I started (8 years) and have NEVER had a problem. 50% canary and 50 % mixed millet. We use the standard mix, not the "Watto" mix. I don't know what weed seeds might or might not be in it, but let's put it this way, there is no patersons curse in my backyard!
My Dodgey mates in WA used to buy a pallet of Golden Cob - maybe that is the way to go?
Cheers
PT