I'm not sure where you are in the UK but I sailed on the Northwest Coast a bit so I'll add my 2 pence...
I don't know your experience level but I'm assuming it's on the low end, no offense intended. I am not well experienced either. One thing I did notice was that steep chop and winds 18-23 knots were common as is a large tidal range. There's a good reason why twin/bilge keels are really popular in the UK as it can be a long sail from one marina to the next and
anchorages where you can stay afloat can also be rare. Protected mudflats seemed a lot more common and for that reason I highly recommend a twin or
bilge keel
boat. I sailed an
Albin Vega when I was there and really didn't like it. Windward performance was poor and in the aforementioned steep waves it was a very wet ride. The
boat was more like a submarine as it had insufficient reserve buoyancy so going forward in these conditions was extra thrilling as the
water would come up and wash over your boots. Also, they are cramped inside. 5'8" is about the tallest you want to be in one.
I've put in about 50 days of sailing (more relaxing at anchor) on a Westerly Centaur and loved it. Even though my Centaur experience was largely in light winds, where it's extra drag makes it a slow boat, I found it very enjoyable. The stability of the design is excellent and the design at the bow provides that reserve buoyancy and a much drier ride. The original
Volvo engines that came in the Centaur aren't great and replacement
parts are ridiculously expensive if available at all so I'd look for one with a
Beta Marine engine instead.
I could go on but it may be unwelcome so if you have questions about either of those boats feel free to send a private message.