Depending on your low-light subject, what about using a flash? In my opinion, that is the easiest solution while retaining a good DoF and IQ. You could go with a f/2.8 and utilize the flash with good technique to stop motion, if that is what you are after. Hell, you probably could get away with a f/4.
Although I'm still a beginner when it comes to photography, I don't understand why flash photography is rarely mentioned. I can understand if the shooting conditions forbid or frown on using a flash but most times it doesn't. I got my 430exII recently and can't imagine how I would do without it now indoors. Even on my 24-105 f/4 IS, the flash is good enough to get me shots of a 5 month old. I can't imagine what a f/2.8 could do for you.