Advice pls

selvalin

I need to replace my old mountain bike an elderly Dawes Tamarak, my budget is £1000 i have selected few bikes that fulfill my criteria but right now i am lost. I am 50 years old so i will use it rides not longer than about 20 miles in mostly flat terrain, the candidates are these.I like the stache but the tyres 2.3 seem to be too thick and heavy maybe?.
Thanks a lot guys.

Trek Stache 7
http://www.evanscycles.com/products/tre ... e-ec054513

Trek superfly 5
http://www.evanscycles.com/products/tre ... e-ec068689

Grand Canyon AL 6.9
http://www.canyon.com/en/mountainbikes/bike.html?b=3640