I agree with the advice to begin on Houzz.com. Look through there to see what ideas you like, and then from there you can decide what materials would fit into your budget. If you have any home shows in your area that are coming up, go to them. There, you will see many companies that do custom cabinetry, countertops, tile flooring, wood flooring, you name it. That can be another way to find ideas, as well as to speak to contractors who fabricate and install all of the various finishes.
When you're finally clear on what you want to do, shop around. Don't be afraid to check out places like Home Depot, Lowe's, and even IKEA for your cabinets. You don't always HAVE to order custom cabinets - and in fact, going with stock cabinets can be a great way to save money and still have a beautiful kitchen.