You won't need waterproof speakes unless you keep the top off all the time. I've never had waterproof speakers in any of my Jeeps and I've never had a problem. Look into this though before you buy:
http://www.lawyersandsettlements.com/articles/Chrysler-complaints

Chrysler isn't honoring their warranties. I feel like an idiot for having bought a jeep. I've never really driven anything else, but my 2004 has so many problems right now and there's...

The Wrangler is a totally fun, but way overpriced vehicle. Quality has always been an issue too. If Daimler sells off Chrysler, I hope GM or Ford buys the Jeep. If you've gotta have one, buy one. (I've got an FJ40). Even though I live in the desert I'd get the marine speakers -- just in case. I agree with the "don't hose it out" advice. Why do that when a shop vac does a better job?

Have fun!

no

if you were to wash out your jeep you might want to paint the inside with a truck bed liner, like herculiner or some other brand! what I did was coat my inside of my jeep and when I built my speaker box, I coated it also with the bed liner! I still wouldn't wash out the inside of my jeep with a water hose. use the wet dry vac with a soap and water wet rag! takes longer but looks better!