Options to Boost Low Water Pressure from City ?

My city water pressure is a paltry 40 psi on my side of the 3/4" meter. My service line is new 1-1/4" sch40 pvc. I'd like to have at least 50 psi for the second floor bathroom but would prefer to not have up and down pressure variations. I don't think we would ever exceed 10 gpm flow and would only rarely exceed 7 gpm, assuming two showers and kitchen sink in use simultaneously.

I was thinking I could install a check valve and a jet pump to pressurize a tank up to 70 psi or higher and then a pressure reducing valve to moderate the pressure to around 55-60 psi output (in the basement) to then feed the house.

Given a typical usage rate of 7 gpm or less with 40 psi from the city...
My initial questions and thoughts were:

1. What capacity tank? Only a portion of the tank capacity would be available before the pressure dropped and the pump would need to come on anyway.

2. What capacity pump? Bigger is better to a point. Bigger is mo money. If the pump can supply 10 gpm or more at 55 psi or more, do I actually need a tank other than to buffer the initial pressure drop as a fixture is opened and then the surge as the pump turns on? and therefore a smaller tank like 20-30 gal?

3. Once the tank pressure drops and the pump comes on the pump is basically in continuous duty mode. Can these pumps take that kind of usage without becoming a maintenance problem?

Am I on the right track?
What are my other options for boosting my pressure? (no little blue pill jokes)

Thanks

Any "packaged pump system" will do the job, if it is installed in the piping properly. A Y McDonald also makes a somewhat "pricey" unit which is compact but will maintain a set pressure during use.

Do you have any preferences as far as brands of pumps? Goulds, Grundfos, Little Giant ?