Patti, This is an age-old dilema - I think the Quilt Police came up with it. What matters more than the number of stitches per inch is that your stitches are even. That means that the amount of thread on the surface is the same length as the space between the thread and that both are the same all over the quilt. This will take practice, but you will get the hang of it.
How you achieve this is a matter of peronal preference. Whether or not you set up a frame is your decision. I had one, but I couldn't master the quilting in all directions. I learned using a hoop - 14" diameter, & I am most comfortable using one. This way, you can turn it 360º so that you can quilt all directions the way it's most comfortable for you. Some people quilt without a hoop of frame. They just bunch the quilt up in their hand & stitch. I'm not sure how they manage a large quilt, but they do!
Good luck & happy stitching!