You are probaby a lot colder and a bit drier than me Jacob.
Jacob Wright wrote:a) good hedging mixes for this area that provide wildlife habitat, stock-proof barrier and foraging opportunities. I was thinking predominantly hawthorn but with some blackthorn, gorse (for nitrogen), hazel, rose, beech, spindle, juniper and guelder rose thrown in.
Hawthorne is great! Blackthorn tends to sucker with me (could be an opportunity to propagate your own bushes though), gorse - horridly spiky, but lovely flowers, hazel for nuts, rose - rosa canina tends to have the large hips of the native roses. Rosa rugosa has big hips and very fragrant flowers (can spread widely by suckers not native), beech - tends to get wind sculpted and likes good drainage, spindle (I have no experience of) juniper may get shaded out in a hedge, I think it like sun, guelder rose again I have no experience of.
I wouldn't discount holly. It grew surprisingly quickly for me on better drained soil and makes a lovely hedge with possible berries for birds or sales.
Prickly is your friend if you want stock proof, most anything else might get nibbled down! You can use sheep to prune your hedges here by using diamond net fencing.
Crab apple is a possibility - not very stock proof, but some fruit very well. I've had surprising success with holm oak with the faint possibility in the future of edible acorns. Small leaved lime has much nicer leaves than beech in my opinion, although I'm not sure how it would take to making a hedge. Oak is slow growing, but makes a good hedge as does hornbean - they both tend to keep their leaves over winter a bit, which improves the shelter for wildlife. Oh definitely consider elder! - good pioneer with flowers and berries for foraging, which will take easily from cuttings too.
For wildlife a few rowans would be good too
b) good suppliers of bare root hedging - affordable, healthy plants with a good selection, ideally east lothian or borders
I've used
alba trees and
scotplants direct. In my opinion though if you can get locally sourced trees that is much better - hazel, oak and birch all seem to vary a lot in their growing and fruiting characteristics, and local ones can have much better survival.
c) any perennials worth putting in along with the hedging plants to accelerate hedge growth miyawaki-style
The only comment I've got there is that I did find that mulching out the grass made a big difference to the initial establishment and growth of my trees. You could try raspberry (they will escape if not eaten by stock) mint, sweet cicely, yarrow, meadowsweet, vetch and clover, and good king henry. Is it worth sticking in some currant bushes? black currant and red currant will grow quickly, and take well from cuttings, gooseberry often has thorns, which may prevent browsing.
Good luck with your project Jacob, and please keep us informed how you get on!