I like the idea of a house of randoms. In a way it is already that with the hereditary inbreeds and party hacks but out of a hat would get make it a fairer form of random. On the other hand Scotland doesn't have a second chamber so I can't see the parallel. I'm not sure about PR; in theory people are supposed to be represented by a government which represents the proportion of successful candidates from each party. In practice what happens is that the largest party does a deal most often with a minority party and that coallition forms government. Other parties with a sizeable proportion of the vote are left out in the cold and are unable to represent their voters. Just as happens under first past the post. Look what happened in Scotland and generally where this system is used.