Add a poll.
Buy HLCD's new, I called Wetsounds directly and they gave me the TX deal since we have to pay tax as they are based in Houston TX.
I would like to add a point here, when being pulled behind the boat at 15+ mph there is a lot of engine noise, and the normal water & wind noise. coaxial speakers just don't cut it (from actual experience from both types coaxial vs HLCD) HLCD's are superior for reach and clarity. I would hate for you to go through all that trouble of installing the speakers and not meet your expectations.
Typical HLCD's
Kicker HCLD
http://www.kicker.com/41KMS674C (low grade)
Krypt
http://www.krypt-towers.com/tower-speakers/ (mid grade)
I had Exiles/Samson before, but never installed them I could not find a good way to add lights so I sold them and took a heavy loss. (if you don't care for lights best value esp... if you can land a demo set)
http://exileaudio.com/store/index.php/tower-speakers/wake.html (high grade)
I now have 1 pair of Rev 10's full loaded with swivel and removal with RGB led's and light ring, I can tell its expensive, but was worth it in the end, they pound my riders hard, I always asked them have you every listen to music when tubing and wake boarding and they always say its 10x to jam out when riding.
https://wetsounds.com/pages/products/REV10.html (high grade)
and some food for thought.
When controlling tower vs in boat speakers I found that Wetsounds offered the best EQ for my needs and liked the functionally better, no EQ is perfect but they do it a little better the other guys.
Another note here, I always leave my Wetsounds EQ volume the same, I change the volume via my Sony deck or swim deck controller so I can adjust the volume with better ease rather than always adjusting from the EQ, you just have to set/fade the speakers to tower-boat depending on what your doing riding or chillin which is a full time job btw esp... when towing driver, DJ, all in one!!!
FYI since you have a tower, then tower speakers make the best swim platform speakers vs the non tower boats, I feel bad for those guys.
Dilemma where does the EQ go?
see through and unmodified fiberglass:
prototype
you can see here, I only needed to remove a little where the wetsounds EQ would slide into, you can see where you need to sand down/remove the little bit of fiber glass to make it fit correctly. (not the final product)
I don't have a pic of it mounted in the boat I will have to go out there another time and get some pics, and I increased the thickness of the ABS plastic and beveled the edge to match the other trim design better, again let me get pics.