E40bx or E50BX

Hi everyone. New to the group here.

I am licensed HVAC contractor that also does energy audits & blower door testing.

I am looking to get this tool to compliment the audits & blower door testing and for other diagnostic issues including mechanical equipment, duct leakage, water leaks, etc

should I go with the E40bx or E50BX. The only difference I can tell is the resolution/pixels. Is it worth $1500 extra for just the increased resolution?

Also, I am wanting to put a lower end camera on every truck in my fleet. Would the cheaper i3/i5 models work ok for standard HVAC diagnostics with my service techs.