I can't offer any specific ideas on plants since our climates are so different. However you have some of the worlds most drool worthy resources for gardening and landscaping (and historical sources) right in your own metaphorical backyard. My bookshelves are filled with wonderful UK gardening topic books (all in storage at the moment), most of them I found through our local library system, university bookstores and recommendations from other gardeners. Makes for great reading during our very long cold winters.
I am enclosing a link for the Royal Horticulture plant search that might be useful for you. They may not be exciting to look at but you can learn a lot just by playing around with different search terms. There are also wonderful UK gardening shows available online via youtube that I find awfully interesting and worth spending time watching especially when I am in danger of going bonkers waiting for spring.
https://www.rhs.org.uk/plants/...