Goat meat (Chevon?) is becoming more popular as TV chefs use it, I think there are a few enterprises starting up here and there, we had a message at our local goat club asing if we had any for sale, but we all rear and eat or sell our own.
powdered milk would be easier to use than milking your own goats, but more likely problems if you don't get the mix/temperature right. and it comes down to time,
I think 6 weeks is too young to wean a kid, and they put weight on better if entire, so if using goats for milk you'd have to make sure they didn't get to the milkers. But then of course you'd have to get them away early autumn before they get smelly, or keep them till Jan/Feb after breeding season.
I'm sure there is lots to think about, but you have sheep + calves, try it. why not chat to local butchers/restarants & hotels, see if there is a market?
I know a butcher who buys cull dairy goats, he bought a boer male off me for breeding with some of these goats, seems to be doing OK, saw him at the farmers markets a few weeks ago, shocked at the price he charges though