I am replying reference the small 12V cooler. Just a comment that just about all small 12V coolboxes are both electrically inefficient and pretty noisy (the one I bought a couple of years back was one of the more expensive 'peltier' models but it still went back after one weekend away!
I fitted my own. Trust me, it’s easy. All you need is a head for heights, and the courage to drill a hole in your roof.
I used Complus Energy 07954 059371.
Next day delivery, came with panel, mounting feet , controller, cables and sikaflex. Very pleased.
It's fine using Bimble if you live on or near the south coast but they charge plenty for delivery. I used Alpha and was well pleased with their service and prices. I did, as you suggest, ditch the pwm for an mppt but managed to sell it on with the MT50 which wouldn't work with the replacement controller.
I personally think when it comes to glass panels (rather then the flexible type ones) there are pretty well much of a muchness and going on price/Watt (delivered) is a reasonable way to go.
Alpha Batteries have good deals as mentioned. OnboardEnergy also often have good deals on panels. And there are some good deals on Amazon to be had as well (got some mid-brand name 100W Mono panels to match my roof-mounted ones recently for under £70 each)