I will post pictures of the set up when I can, boat is under a cover right now but probably will be broken out for the water this weekend. I have a small plate that positions the motor in such a way that the shaft is over the gunnels and I have 3 series 31 batteries that fit just fine in the console directly behind and beside the cables. It seems to me that Parker must build these consoles with the idea that you may be sticking 3 big batteries in that console because they fit perfectly.
As some background, I was set on the 87 from advice on THT and this site, but my local Parker shop insisted that the 72 would be fine. I trust my local guys and went with the 72. I've been out in some snotty weather and still able to spot lock without any cavitation. The worst day we had to call it because my two "crew" were throwing up over the side, and the wind was 20 mph+, yet the spot lock was working great with no cavitation.
Maybe if you were a charter captain and simply couldn't risk having to go out in miserable conditions and having cavitation problems I suppose the 87 makes sense, but for me the 72 fits the bill just fine. However, don't mistake any of the above for expert advice.