Not sure that we have found the best way of keeping them yet. Ours have been kept in coops on the lawn .... small hen coops. They are now in a large wire run with a box in for shelter/ warmth. They survived in coops during those hard winters of a couple of years ago .... we are at about 800ft. We did cover the coops at night .... when it went very cold ..... below say minus 10.
I think they are happier in the cold than they are in the wet. Our grass gets sodden in the winter and so we are going to try rabbit type hutches next, maybe with a run underneath so that they can be on grass in the summer.
A neighbour had some eggs from us to hatch and built a wonderful aviary. However, she didn't find it easy as it quickly became soiled and needed frequent cleaning. Even though she wired a way underground the rats dug in and killed her quail in the end.
Any coop on ground/grass will need a wire base to the run ..... that strong, small squared stuff. Rats WILL take them.
Food. You can get special quail pellets. We can't buy locally so although we have tried them we usually feed layers mash. We worm with Marriages with Flubenvet. I used to grind it up but have found that they eat the size of pellets fine.
Ours also have a tiny sprinkle of mixed corn .... no problems with this yet.
Good idea .... stick to the girls. Always best!

Males are VERY aggressive. We also found that females showed quite aggressive behaviour to newcomers. Sometimes difficult to get them to accept new females added at a later date ... even with wire between them.
They love a dust bath and conifer branches to hide in.
Not sure of best place to buy from. We have tended to hatch our own. I don't find it as easy to tell their age as you would a pullet from an older hen so need to find a reliable breeder.