How much powder coat should I order from Eastwoods?

I will be powdercoating the lower and upper control arms, end link rods, drum brake backing plates, spindles, and rearend shock mounts, rear leaf spring mounting bracket, and a few other odds and end pieces. I have never had powdercoating done before; I want to use cast gray for these pieces so I will have to order the powder for the shop to use. How much should I order? Thanks

I say it can be done with 5 lbs, but best to have 10 lbs on hand, just incase,.. depends on the guy spraying,....IIRC Eastwood will accept powder return if the bags aren't open