Yep, a wider tire will help you on the pea gravel. Take yourself and your bike to the shop, they can show you how to measure your fork so you will know what tire width you can use. Sounds like you don't have fenders so if you plan on adding fenders they can help you take that into account as well. You may be able to look your bike up on the internet and see if the specs say what tire width it can handle but just as easy to take yourself to the LBS.