The only reason to go with one of the zooms would be convenience. It's just easier to zoom than to change lenses. I really don't think the 55-60 and 60-70mm gaps are a matter of much concern. 95% of the time a small shift in position will compensate. The only time it won't is if you can't move position for some reason, or if you are shooting a distant scene where you'd have to move a lot to change the view much.

Of course both zooms will yield higher quality images than the 18-55 kit lens and both are faster, so you'd gain something in image quality as well as the convenience of a zoom. Of the two I'd probably go for the EF 24-105/4L IS because of the wider zoom range and the fact that it has a very effective IS system. I have this lens myself. It's not perfect in that it does show some distortion at the wide end (especially noticable with full frame cameras), but overall I like it a lot (and the distortion can be corrected in DPP).

The EF 35/1.4L is a great lens if you do much low light work or you need the fast aperture to minimize your depth of field. It will also have a little less distortion than the zooms if that's important to you.

In the end it's really  a matter of personal choice more than anything. All three lenses are good and it's basically what appeals to you and is most useful for the way you work.