Kudos for getting this page together. I've only ever had mediocre results with Cotman watercolours which can give muddy results and I absolutely disagree with buying cheap paper. When I started buying the most expensive watercolour paper I could afford (300 gsm) my watercolour practice got much better. Obviously that is just my experience and people have to work out what works for them. I'm on Instagram @chloegilbertartist and if you scroll you will get to my watercolours.
I get Strathmore, the largest size I find then I cut it out smaller with the help of a cutting press (free for use at Fedex/Kinkos or Office Depot). It helps save a lot of money that way.