i haven't owned either, but i've also been doing loads of research for the past year or so in preparation for getting both species in the very near future..so maybe some of the things i've learned may help? i also have a bonus of my roommate growing up on a goat dairy lol.
goats are great for milk and meat - but you'll need two different breeds to accomplish both. generally i've learned that "dual-purpose" breeds aren't really worth it. if you want milk, get a milk goat. if you want meat, get a meat goat. a dual-purpose will basically be sub-par at both jobs.
the milk goats on my radar have been nigerian dwarves, lamancha, and nubians. nigerians are smaller, produce less milk, but have a crazy high fat content so their milk is very rich and creamy. i've heard many people say their milk is the best. nubians are larger, have the cute floppy ears, and are good producers with good milk. they tend to be easier to milk since they're bigger. lamanchas are basically the premiere milk goat - they look goofy with little nub ears, but they are large and produce TONS of quite good milk. this is the breed my roommate's family used on their farm. i personally am going to go with nigerians as we don't drink a TON of milk, and the smaller animals will be easier to handle. i love nubians though...but we'll see how much milk i end up using in crafting, etc. there are also mini nubian and lamanchas available too, which are smaller than a standard nubian or lamancha and produce less milk than their parent breed, but more than a nigerian.
as for meat goats, i haven't really looked much into the different breeds because i have family that has raised boers as long as i can remember and they're the most popular meat goat here. i had basically decided on them as soon as we decided to buy property because they're good goats and i can easily acquire quality stock from relatives.
i want to have wooling and meat sheep so i can't make suggestions on hair sheep. i still haven't decided on a breed myself because there's SO MANY and i'm not sure what's available in my area that provides what i'm looking for. they all kinda seem to be around the same size though. milking sheep do exist, but i've never heard if the milk is very good or not.
it's also worth it to consider their lawncare implementation as well. goats are more browsers, and prefer to clear brush and eat just weeds and bushes, whereas sheep are grazers and will mow your lawn for you. goats WILL graze, but pretty much only if that's what's available. they'll much prefer to clear your pastures for you instead. goats tend to be more stubborn and adventurous, where sheep are more herd-oriented from what i understand. goats like to climb, so proper fencing is very important. horns vs disbudded is a personal decision, but horns will make things a tad more difficult as they can injure themselves/others/you more easily and get caught up in things as well so you'll have to take extra precaution with their environment and supervise hierarchy disputes more carefully. overall though they are quite similar in their care.
