With lenses on sale, I need some help choosing

I've been debating buying the 50mm 1.8 ($90 at Adorama when added to the cart) or the 1.4 (which is $300 at Adorama when you add it to your cart). I'm using a 60D and have the 15-85, 60mm macro, 55-250 (not really relevant to this post) and the 430 EXII. The current main purpose of adding an additional lens would be for pictures of my (almost) 5 month old daughter now, and in the future.

I'm not a huge fan of flash as I think that it renders unnatural colors. The obvious solution is faster lenses - hence my above internal debate. The problem is, I'm not sold on whether or not 50mm is the focal length I need. I'm wondering if either of the new 35mm lenses (Canon's f/2 IS or Sigma's f/1.4 - probably the Sigma due to the larger aperture) would be better suited to my needs.

The more I think about it, the more I think the 35mm focal length is the better solution - but this being my first child I admit I don't have much experience to go off of. Currently, I'm using my 60mm macro wide open and standing (or lying) a fair distance away. Occasionally when more versatility is needed, I'll use the 15-85 with the 430 EXII (but as I said, I'm not a fan of flash).

I'm wondering if I should reserve the 60mm macro + flash for occasional use and go with either of the 35mm's for majority use.

Is anyone with a similar shooting situation able to chime in and help me out? If you recommend a 50mm, is the f/1.4 worth the extra $210 over the f/1.8?

Heck, maybe even the 35 f/2 non-IS is the way to go since the major criticism I've read is that it falls apart at the corners and since I'm on APS-C, that might not matter as much. Any thoughts there?

Thanks!