water tank pump

[atcompton]

I have stripped down the old Evenflow 600 this year for the last time. I think it's terminal and I am buying a new pump. The tank is under the floor, so a submersible would be tricky to fit. The old pump served the sink as well as a gas shower fitted in the back, which I have now removed, so the pump probably can be less powerful
Question is: There are loads of similar pumps online, varying from £13 upwards. Should I buy a self-priming pump ? Is run-dry important and what flow/ pressure do I need just to pump drinking water from tank to sink?

Suggestions/ recommendations welcome