Admittedly the sensitivity of your speakers is under what Bottlehead recommends. But... always the but, there are several things that factor into this.
How big is your room, how hard/soft is your room, how loud do you like to listen and what kinds of music do you listen to?
If you have a 20' ceiling in a 32'X18' room (obviously you don't), your room is overly damped, you like to listen to hard rock at concert volumes then you will be in trouble. Considering that a 15WPC tubed PP amp now increases your chances. Your other thread will help also.