Zwarbles are pretty hefty which might not suit you.
Your dream sheep will be specific to you, so all we can do is make some suggestions.
The weather and climate of Scotland is very different from much of England, so it could be best to concentrate on local breeds, adapted to Scotland.
The rare breeds are in need of support, especially North Ronaldsays, Soay, Boreray and multihorned Hebrideans. See the thread about 'rare breeds at Lanark Mart' - Palacerigg, which just received its RBST approval, has had the rug pulled out from under it by the local council, so there is a one-off chance to buy some of those sheep, on this Saturday at Lanark. It would be lovely to see them stay in Scotland.
These are little sheep, so the meat carcase is lighter, but makes up for that in wonderful flavour.
For appeal to visitors, the Hebs, especially the multihorns, are stunning.
There are other rare breeds, some suitable for the Scottish climate - look back through past emails on this topic.
Another Scottish hardy breed, although no longer rare, is the Shetland. These come in white and a huge array of other colours and patterns. Added to all the other benefits of the smaller primitives, Shetlands grow a lovely fleece, which adds value and interest for your visitors, the possibility of having their fleece spun at a mill for sale in your shop and a new craft for you to learn.
You can also have the skins tanned for sale, another added value, and the tups have horns which can be used to make buttons, pendants or crooks.
You mention you have children - Shetlands in particular are great for kids to show. They are small, easy to train and handle, and many breeders will be delighted to help with advice and friendship. Some of the other breeds can be too big or too feisty for children to take into the show ring.
I keep the Ancient Type of multihorned Hebrideans and a couple of Shetlands, but in the past I have kept Jacobs (that's another breed with the wow factor, good fleece, beautiful skins and they are ready for slaughter in their first autumn), Gotland, Manx Loughtan, Soay, and some down type crossbreeds for fleece sales (a bit too wet here for them really)
Of all these breeds, only the down types lack the extra taste of the Primitives. This develops in particular in sheep which are reared slowly, so if you are not restricted for space they are a great bet. The Jacobs I mention above are pretty tasty too. Top for us is Hebridean, but I do appreciate that many breeders need a quicker return.
