Surely the cheapest option is for non English to stay away from The House when devolved matters discussed. Then you would de facto have an English Parliament and a British Parlimament with no extra cost.
I agree Secretary's of State for the devolved regions should be an MP from that region.
Agree The Lords should be looked at. At the moment undemocratic and expensive. I do appreciate they do have a function of reviewing leglislation but are so many required.
In USA Senate has only 100 members . Our population 1/5th of The USA.
20 members might be a bit small but surely 50 full time members should be able to cope.