I do not make mine a bread bowl and I use a generous amount of Old Bay seasoning (you can google substitutes if you don't have any). I tend to use less cheddar cheese but I like the idea of using white. A dash of worchestershire adds nice depth to the flavor. If you can find fresh crab, definitely use it, and use backfin if you can afford it. If you can't find fresh, I would choose canned over those fake krab bits in the refrigerated section - they taste nothing like crab.
Here's what I do,
I sautee garlic, crab, and artichoke hearts in butter in a skillet, I add cream cheese, asiago, mozzerella, and parmesan and romano, let it all melt together, then it's done. I like to serve mine with warm soft pita bread.
Sometimes I add spinach too! Ooooh I'm so making some tonight now!