Looks like there is 20% off saddles at the moment although I didn't catch the code it should popup for you.
No schwalbe marathon pluses in 700c unfortunately :(
Schwalbe Century's look good for effectively £6.40 each plus postage. Good for a owner of a 29" mountain bike who wants some road tyres. https://www.planetx.co.uk/i/q/TYSCCEN/schwalbe-century-wired-tyre 700x50 size so effectively 29" x 1.95"