That is exactly what I have right now, the 17-40 and 50 1.4. The zoom is a fine landscape lens, but I don't like it for indoors, it's too slow and needs to be stopped down a little bit to get really good sharpness, which makes it even slower. The 50 1.4 is a fine lens. It is soft wide open, but it's fast enough that I can stop down a little and still get nice natural light indoor shots during the day with window light. I often shoot close up shots of my kids at 2.8 and it is gorgeous. I can't imagine anyone not liking that lens.
That being said, if you are going to buy both new, you're going to be getting close to the price of the 17-55 2.8 IS. I would take a serious look at that before buying the other two. I'm thinking of getting the 17-55 to replace my 17-40 and 50 1.4. That way, I'll have one sharp lens with better range and IS as a bonus. I don't know if I'll actually have the heart to part with my 50 1.4, but I have a feeling that once I get the 17-55, it's probably going to spend 90% of the time on my camera anyway. Sure, it's EFS and I'd like to have a FF camera someday, but that's probably far enough out that I'll sell it when that day comes. It'll be worth the loss to get a couple years of use out of the lens.
Good luck with your decision. Depending on what kind of shooting you do, you may be completely happy with the 17-40 and 50 1.5 pair, but I think there are more flexible options you should consider too.
I have a bunch of samples from both of these lenses on my gallery if you'd like to look.
www.pbase.com/billhuegerich