Rock and roll speakers?

R&r, you are welcome.

Easy question, easy answer. The reason is the high efficiency and relative affordability of those. Tekton and zu are other similar options in that regard.

Find two pair of late 70's "Large Advents" and stack them. You can re-cap them, re-wire them, re-terminal them, tweek them, and you will not have spent alot of money.
If going the JBL route, go for the L-150, L-112 or later 4312 series and turn down the controls on the mid and tweet or you will burn your ears off. Others I would consider are the big PSB golds, Vandy 3, Heresy not a bad idea.

Consider a new pair of JBL L890s. They're a bit more than your budget, but they are often heavily discounted. Just keep your eyes open and see. I got my pair for $800 and free shipping.

Horn loaded speakers are a good choice. Older Altec 'Voice-of-Theater', JBL, Klipsch come to mind. I had the 4 piece Infinity RS1Bs at one point and they certainly could move a lot of air.

Anyone wanting to create volume needs to understand the speaker sensitivity rating. Currently your recommendations here range from a low of 87db to a high of 99db. This rating and the amount of power used determines the maximum volume of the system.

Every 3db lower in speaker sensitivity will require double amplifier power for the same volume capability. So if you have 50w on the 99db speaker, then the following would be the required power for lower sensitivity speakers to have that same volume capability,

96db -- 100w
93db -- 200w
90db -- 400w
87db -- 800w

IMHO, I doubt any speaker with a sensitivity below ~93db will be suitable for your situation.