Welcome to the forum!
"I want it to be loud and obnoxious...." I already feel sorry for your neighbors.
When shopping for speakers, it's best to go out and listen if you can. I think that one of the specs that you'll be interested in is the sensitivity (rated in dB) of a speaker. The higher the sensitivity, the louder a speaker will play given the same power input (from an amp or receiver). Klipsch, I think, generally have high sensitivities.
The sensitivity is often the sound level that a speaker will produce one meter away from the speaker when one watt of power is input. Depending on who you talk to, twice as loud equates to an increase of between 3dB and 10db. So, a speaker with a sensitivity of 95dB will be able to play about twice as loud as a speaker with a sensitivity of 85dB when supplied the same amount of power.
One other thing to keep in mind is the impedance of the speakers. The lower the impedance (rated in Ohms), the higher the amount of current that your amp or receiver will need to supply to the speaker. Some receivers or amps struggle or fail to power low impedance (4 Ohms or lower) speakers.
Adam