Re: Quad Cities Iowa or Kentucky Lake for the 4th?
I'm familiar with Kentucky Lake. MI9's post is all very good information. I'll fill in some.
There are many small privately owned resorts on both Kentucky Lake and Lake Barkley that may be attractive to you. We stay at The Moors Resort, located about 7 miles south of Kentucky Dam on Kentucky Lake. But, for the 4th of July, it may be tough to get accommodations or a slip. It's worth a phone call.
http://moorsresort.com/index.html
MI9's caution about water depth is also good information. At summer pool, the shallow water threat is much greater over on Lake Barkley. One can boat the northern parts of Kentucky Lake mostly worry free, but of course have a map and pay attention.
Another note of caution is to make sure your boat is in good running order. Kentucky Lake is quite wide at the north end and if you're in the middle of the lake and you have problems, it's a lonnggg way to shore. Take a marine radio. There also will be occasional commercial barge traffic in the channel on the eastern side of the lake.
All that open water can also create hazardous boating conditions if a line of thunderstorms blows up. If you're on the east side of Kentucky Lake and weather blows up, you may consider staying put instead of trying to race back across to the marinas on the west side.
The boat ramp at Kentucky Dam Village State Park is by far the best, public or private. It has lots of parking and prep area. The ramp is four-wide and not too steep. Farther down the lake, Kenlake State Park has a good ramp, but parking is limited. Most of the private resorts will have ramps.
This website covers the area well:
http://www.explorekentuckylake.com/index.htm