'will it  prime ok'? 
      
If the  pump is  higher than the top of the tank..  No-  the first time will need to be primed.    A  foot valve at the bottom of the draw pipe  would really help after the initial prime.    The pump's  flapper valve  probably won't hold enough vacuum to hold the fuel in the draw tube, especially when  the tank is being moved.  Totally stationary?   it may be fine.

if the pump is lower than the top of the liquid,   it should be self priming (after the initial prime)  as the  fuel still in the pump, plus the fuel in the pipe between the top of the pipe and the pump should be enough to  prime it again.  
Easiest way to prime it would be to put a blow nozzle in the  vent, and  open the  fuel nozzle until fuel comes out.

the price difference between the 2 inch, and  smaller pumps really isn't a factor..  
a  Honda  160 would be plenty to run a 2 inch pump  at part throttle/flow... and they are cheap.   It's gonna work itself to death if you'd  want to pump water wide open all day long... and a  190  would be  better.   
But, for pumping fuel through a nozzle,  the 160 works great here..  (you better hang on to the nozzle!!  it's gonna have some 'kick')