I'm pretty sure you've got to use whoever has service to the house, whether that be CSU/BTU/Wickson/Wellborn/Atmos whatever. I'm unaware of having options for your primary utilities, but I may just be completely unaware. For instance, our last house in south CS had BTU elec, Wellborn water, and CSU sanitary. If you're in that situation, you need to provide your water usage from Wellborn (during winter months when you're not watering your yard) to CSU so they can accurately bill for sanitary. Otherwise, you'll get charged the default highest residential rate.
Everybody loves to hate Optimum (formerly Suddenlink). Their customer service sucks and they will increase prices randomly. I used them for almost 10 years and had no complaints other than the above. Very few outages or service interruptions. I believe they've actually got some competition now, but I don't think it's any better.
