Sounds like you guys need some kick panels!
Beej, I have never heard those JLs in person, but I have had pretty good experience with some of their other speakers. I ran their entry level TRs (5x7) and they got dang loud and sounded alright. Not a ton of midbass or exceptional detail, just loud and decently clean. I then ran a set of XRs and they were quite a bit better. Still got loud, more midbass, and the highs were crisp without ripping your head off. They don't like a ton of power thrown at them if you send them anything below 100hz though. At reasonable volumes, or with th appropriate crossover setting, they do well. I now use them for rear fill with about 75w RMS getting 90hz and up and they've been solid for that purpose.
I would imagine those JL components will be even better. I haven't priced them to know what your budget is. That said, if you can swing it, I highly recommend Boston Acoustic Pro60s. They are well known for handling GOBS of power, good midbass, and staying very clear even at ridiculous volumes. I've been extremely happy with mine. I run them active with considerable tuning, but they sounded great even with the passive crossovers that come with them.