I get your guilt. I think it's normal to worry about how the company will fare without you, and how your relationships with your soon to be ex-colleagues will be affected and what not. However at the end of the day you do what's best for you and your family, mentally, financially, you name it. And you must always remember that throughout this process, regardless of what's going to happen.

There is absolutely no guarantee some people won't be upset and won't take it personally and there is no guarantee the company will have a smooth ride without you, but what you can do is give them plenty of notice, say 2-3 months. During this time you can work with them to make the transition as smooth as possible, including training and/or hiring a successor. Whether those months will be good or a total hell, only you can guess - and you may still be wrong.