I've now read through some of your previous posts and I'll be upfront in saying you still have a HUGE amount to learn about the UK as well as a VAST amount of research to do before you should consider moving this idea forward...
I'm not a horseman myself. Though Living in a rural area which is near a major city I do know many people who are... And do both Fish and Shoot myself so I know a little of how the 'country scene' works...
You've named a few areas of England (not the UK) and an item of Ladies underwear! Which tells me that your research is inadequate. Northumberland and the Scottish Borders for instance are prime equestrian country. Manchester
isn't particularly... And in your position I would be thinking about going somewhere that horses are very much a way of life...
With that said though, as vvaannmmaann has pointed out, the Equestrian market is already well served, and largely by people who's enthusiasm for and knowledge of the local horseriding scene overrides any other concern. What would differentialte your business from any of these?
You will probably have tried and failed to sell your products by mail order? And the reason for this is that individuals (by and large) don't want the risks and hassle associated with personally importing goods. An item from India, China or Hong Kong (where part of my own family are) may seem temptingly cheap. But there is the risk of heavy import duties, shoddy goods, and difficulties in getting recompense for the latter...
So rather than a shop in the UK what you actually need is a UK based distributor who can import the items and offer UK consumers the full protection of UK consumer law. So frankly, what you need to be doing is finding existing suppliers to the UK Equestrian market and asking them to add your products to their range... NOT setting up a shop yourself which is bound to fail!
As for attempting to gain residency; you may find that harder than you think!

On a business basis you would need to be investing considerable amounts of capital in the business and have a very thorough, well-researched business plan. Even then it's by no means as easy as it might be rumoured!
http://www.ukba.homeoffice.gov.uk/
Is the place to start...