For harder longer walls you really need walking style boots, as your feet will get hammered otherwise (unless you’ve damaged the nerves in your feet to such an existent that you don’t feel anything!). The classic boot would be the Sportva Trango. Be warned that any boot will get seriously worn out on a wall (instep and toe) so you will need to either repair the toe after a route, or beef it up beforehand. You can do this by adding more rubber to the toe (to create a bumper), from an old mountain bike tire, or a section of climbing rubber (having grip is a good idea). If you don’t want something so clunky, then go for the stiffest shoes you can, but with any shoft shoe (guide tennie or Camp 4) after only a few pitches they will soften up. Did 3 routes on El Cap this year using shoes that were way to soft, and my feet really didn’t like it, plus having comfy feet is vital on hard aid. Plus they started the trip new, and went in the bin when I went home!
Hope that helps.