I have used all of those phones.
The z10 - if you don't mind not having the latest and greatest apps it's a good phone, but not the best IMO for touchscreen keyboard.
Htc one, great look and great to use, keyboards good.
S4, save your self loads of cash and get the s3 instead, I use the s3 day to day and its a good phone, I came from a 9800 blackberry and hated non physical keyboards but the s3/s4 has been the best replacement yet.
Or get a iPhone 4S or 5. Because they do just work, keyboard isn't as good IMO.