Sheri,
Hot Lips will do fine in the heat if you have it in a well draining spot. Mine is in a Full Sun location, sandy basically unimproved soil...( just mulch that has weed cloth under it.) I never water it unless we have gone a long spell without rain. See pic below.
You might also try "Forest Fire", as well. It doesn't get quite to the 4 ft. height but will top out around 3 ft. Plus a bonus is it set's seed.
Salvia miniata can get to over 6 ft.
Others you might try are Purple Majesty, which here can get 4-5 ft, but does appreciate some afternoon shade.
Sorry I don't have a pic of Salvia Forest Fire but you can google it.
Pics below Salvia Hot Lipx
Salvia minata - Plant and close up of bloom
Salvia Purple Majesty
