Eh... you're not going to get one lens that covers F1.4 and the zoom range you want, or any zoom for that matter, with that aperture. Best you could do is F1.8, right now, and that's one lens and it's not covering the focal lengths you want. Second best and most common is the F2.8 range of zooms. Basically 24-70 and 70-200 all at F2.8, but that's two lenses. Also at $400 new, you're not looking at any premium lenses, which is where the wide aperture exists in zooms. You're looking at entry and budget stuff. At best, you can keep your zoom and just get a shorter focal length prime that is sharper and wider.
If you're happy with the 18-135, stay with it.
If it's the 50 f1.4 that you're not happy with, then sell it. Put that towards your next lens. Make it a prime. Look at the Sigma 30mm F1.4 Art. Look at the Canon 28mm F2.8 IS. Look at the Canon 35mm F2 IS. Maybe even look at the Rokinon/Samyang 35mm F1.4 (and get it chipped).