Hi Oly
I like the ideas you have, it's what a lot of us are aspiring to or already do on our own little patches.
It does sound like you've got a lot on your plate and without wanting to sound very negative, I would say to be careful not to add too much more on. I think you need all your energy to go on current projects if for no other reason than that's how you'll pay for the animals you want.
IME Animals have an annoying habit of picking the worst time to break out or look ill or do something you don't want. A lot of things don't get finished or take twice as long because I have to stop and start. And for all the flexibility in the world you can't be in two places at once; as someone running a small farm on my own that is my biggest issue and the most stressful one. If no-one's home when something happens it's a real pain.
I'd agree that you could take some hay from the fields for now, it'll need to be cut anyway to keep it in good nick for future animals. But when things have calmed down a bit for you and you're going to be around a lot with fewer demands then why not get some sheep (or indeed cattle).
I did think you could start with some lambs, pick them up in the spring or early summer, keep them til they're ready to go to slaughter, they'll mow the grass while it's growing so you don't have to, then come winter the land can rest and so can you - you might even get a holiday in! I did like the comment that if you need one you're in the wrong job - ok if you're a full time farmer but modern day smallholders having a day job as well probably do need it!
The lambs won't need to be sheared, you can probably pick them up already vaccinated and even clik'd for the summer, so minimal intervention required from you, no expensive meds and injectors/applicators to buy, minimal feed cost maybe just to finish them, you can just enjoy them!
You don't even need to focus on picking the one right breed if you get different ones every year, it might help you decide what kind you'd like if you ever go on to breed them although with a very small acreage that may not be viable. You'll have meat for the freezer and skins for rugs, could be an income stream for the guests or just a pleasure to have for yourselves.
I recently bought a handful of lambs to add to my little flock who were already treated for everything, I won't need to do anything with them before they go to slaughter - a responsible breeder will advise you. I keep/breed Shetlands but these little guys are a mix of crosses bred for fibre so coloured Ryelands, some Corriedale, bit of Shetland, and they are a gorgeous bunch. I do have a few white ones but more of the coloured ones and it's nice to see a real mixture esp as I do want the fleece for wool.
I don't think you have the space for full grown cattle but similar to lamb, rose veal calves take anywhere between 6-10 months to reach slaughter weight depending on breed. There are threads on here which I have read as I was interested in doing this once we find a bit more land. They will need housing and feeding with concentrates and silage etc so more cost involved than the sheep, so perhaps when the barn is rebuilt it could be a goer if start up costs aren't a big factor then?
Good luck with whatever you decide to go for.