Well i can only tell you from my experiance. I went to Key Largo, and stayed at the Ocean Point Suite's, for two reason's, #1 it's on the Ocean side, you pull out of there own marina, which the slip is about $25 a night, well worth it, i kept my boat in a slip at their marina the whole time for the week, i love that, not having to take it off and on the trailer. Second reason i stayed there, is cause it's not that far from alot of the Upper Key's main attraction's, all the wreck's and reef's are approx 8 miles to 12 miles out of Ocean Point Suite's, and your in the gulf inshore, so most of the time it's calm.
If you pick a " waypoint " and hit " goto " , most hand held gps will give you a road to follow, i picked a " route " going from waypoint to waypoint , going around the low spot's , and didn't have any trouble's at all. Matter of fact , it was my first experiance bringing my own boat down to the Key's 6 month's ago, and navigating around.
It wasn't hard at all, matter of fact, we dove all day, and dove every night till 1 am hitting all the reef's, the Benwood, etc, and had no trouble's navigating at night either. Luckley , we never did hit ground, though we came close our first night, at Mollasases reef, i din't know they had moaring ball's all ready there so you don't disturb the reef system, but we had a ball !!!
In all honestley, my day's are done with diving off crowded dive boat's, telling us where were going to dive, and how long we can stay down.
I say go for it, sound's like your fully equiped, ready to have fun, it's not that hard to navigate, you just have to " get to know the water's " down there, and by the end of your trip , you'll say it wasn't that bad at all. You do have to watch all the time, and pay attention to your route, there are alot of low spot's , but im sure you'll be fine, have a blast, you'll love it !!!
One last thing, if you pick a place to stay in the upper Key's, and are going to keep going where the Speigal Groove, and all the wreck's etc are, try to pick that side, cause navigating at night if you plan to night dive is a pain for me from the other side, plus it add's about 25 min onto your run time, just a thought !!