Find the tire style you want and then choose the one with the least rolling resistance. When you do decide and make your purchase, look at the sidewall to see what the maximum inflation pressure is. If you want longer life and do a lot of highway miles, they run your tire pressure a "little" higher. For example, if your max sidewall pressure is say 45 psi, try running your tires at 38 psi. Higher tire pressure keeps heat from building up. Excess heat will break down your tires faster internally. You'll also get better fuel mileage over time. If you're carrying heavy loads in the vehicle, you'll want to run them a "little" higher than normal while carrying the loads to compensate. NEVER exceed the max on the tire sidewall.
Check your PSI as soon as you get home with the new tires. Chances are that will not all be the same from the tire shop.
Yes, higher PSI will make the ride a little stiffer on bumps, but you have to decide what tradeoffs you want and can live with. Everything has trade offs.