A lot depends on where you are and what climate you have. I'm in north Cumbria with 50" rainfall a year, so the land you describe in my area would support roughly 1 breeding ewe per acre. Further south, or somewhere drier, you may manage 3 or 5 times that number.
What breeds do the local farmers have on similar ground? That would be a good place to start. Do they sell lambs as stores (not full grown, someone else will grow them on and sell them 'fat' - ready to slaughter) or do they fatten their lambs? Fatten and away by autumn or are they kept on and finished and sold the following year?
If you have bog you will have midges and flies, unless you also have constant wind. Flies could mean flystrike, so for low maintenance you may want to look to a self-shedding breed, but if you are somewhere inclement then the sheep will need more fleece than that.
Easily lambed is one thing, but you do need to be present when sheep lamb to help if there are problems and to ensure there's no mismothering, mixups, that the lambs get onto the teats and get their colostrum, etc, etc. Will you be able - and willing - to take holiday from work for lambing time? If not, then don't get breeding sheep, instead buy store lambs and fatten them.