Hi there and well done for deciding to use and tidy up your ground yourself
Like Fleecewife, I'm not a goaty person but my understanding is that they aren't
grazers, so perhaps wouldn't do much to improve the grassland.
Native / primitive sheep, however, would do - and are not, IMO, boring! Have a read up and a look on the
RBST website, try to get to some shows to have a look at some (The Royal Highland has gone, but there's the Scottish Smallholder and Grower Festival at the end of September
) and decide which you like the look of. Or do as I did and buy a few of a few types, to learn which ones you like working with.
For your ground I'd be looking at Boreray, Castlemilk Moorit, Hebdridean, Manx Loaghtan, North Ronaldsay, Portland, Shetland, Soay. All these breeds have their fans on here
. If you like multi-coloured then you can rule out Castlemilk Moorit, Manx Loaghtan, Portland. And would have to choose your Hebridean and Soay carefully to get a mix of colours. If you prefer horned that would rule out Shetland (unless you buy up wethers, which would certainly be an option.)