Jacobi, I'm going through the same thing as you right now. I've decided I want guts instead of Obligatos too, but for different reasons (I like the sound and hate being in pain).
I've done some research, and I've found that most people say that you will get a decrease in volume using guts.
If you really want to research about guts, read
www.rockabillybass.com forum posts. Rockabilly guys almost all use guts or nylons, and it seems the vast majority here use steels.