Why don't you have a quick google before making stupid comments?
I’m confused to what it is you want.Do you want to connect what you have posted above to your shurflo (that strainer will connect direct to the pump), or are you asking ‘what john guest fittings do you need’?
Look at my post above have set several vans up with jg fittings
I use John guest 15 mm pipes and fittings central heating combi boller fitting fits to the Sureflow pump inlet/outlet
Use this for your tank:https://purefreedom.co.uk/large-tank-outlet-fittings-kit.htmlYou can the double jubilee clip the hose onto the barb. (There are different sizes, just get the relevant one to the hose you want to use)Those plastic ones you’ve listed above have the potential of breaking a little if you tighten the jubilees too tightly.