In noisy aircarft (and I class Lycoming/Continental SEP as noisy) you have the choice of light and relatively expensive ANR or heavier and moderately high clamping force passive to give decent performance.
You need to be up in the Lightspeed Zulu/Bose price tag area to be really good and light. They are worth it if you are going to be flying a lot of hours, and long flights.
What is your hearing worth to you (or going to be like in twenty years time?)
In any case, make sure you try on your selected choice for a decent length of flight - a good pilot shop will let you borrow a demo set (if you leave your credit card number in case you don't come back).