First of all, please place your questions here, so I only have to answer once and not individually, thanks.
The spade lugs are only available in bare copper.
No, there is no brass version of the binding posts available.
Yes, the threat on the binding post is metric (M4), not imperial.
Please find the price per unit for the asseccories below:
Spade lug 12-14 T2 Copper $1,00
Spade lug 22-16 T2 Copper $0,60
O ring tongue 16-22 T2 Copper $0,60
#8-32 T2 Copper Hex Nuts $1,00
DavidKo
The posts are as they are, I haven't designed them, I just help with the EU group buy. What I can comment: In some cases you don't need the light guide, but need the space due to front panel thickness, this is why you have both D-shaped tubes in the set.
-branadic-