OMG what a great topic! That is sooooooo my problem. You have SBI right? Did you read Ken's PDF on Why People Fail? (I wish he had a link so I could post it here 'cause it's great!) I am the one he described as the "Ready Set... Ready Set... Ready Set...." type. I have all these ideas and I just have trouble saying "GO!" I think it's a fear of failing and I overthink things.
I don't think it's a bad thing, we just have to learn how to focus our energy on one thing and not get distracted by so much. For me it helps to make a list of "To Do" everyday. But one thing I did learn is if you aren't making any money yet, you have to focus on one site at a time. I tried 5 different sites at once and because I really didn't understand how to market and get traffic they all pretty much failed. So instead of focusing 100% in one venture, I ended up devoting 20% to each site. Bad idea when you're learning. I was all over the place.
So now I'm going to do my sbi site and that's it. I spend time reading everything Ken writes and when I narrow my concept I'm going to make an outline of my content. You got to have that before anything otherwise no one will come visit your site.
Like you I have a full time job and really want to do this web thing full time but I've really got to get focused. So yeah I feel your pain!!