I would recommend googling pumps because there are so many makes out there and you want to make sure you make a wise choice.

I wouldnt think you could go wrong with a goulds pump unless you choose the wrong style or capacity. But you said 45 psi, that pump max is 40.

The best recommendation I can give you is to purchase a pump that is readily available in your area. I would not recommend buying a pump from Lowe's or Home Depot. The reason for this is, they are not the same quality as the pros use. Every manufacturer (Sta-Rite / Berkely, Goulds, Meyers, Jacuzzi, Grunfos, Flint & Wallen and Etc) makes high quality commercial pumps. Most of these pumps are prevalent to different areas. Choose one of these at your local distributor, and they can size the model for your needs. The other reason for choosing a pump that is prevalent to your area, is parts! They will be available. Good luck!