There’s not a lot of free Genesis-compatible hair out there, at least in my experience. If you join the Platinum Club for a month ($30) you can grab a bunch of hair (and other things) at $1.99 each, so if you have a budget of $50-$100 or more that could be a good way to go.
Keep in mind that hair that hair that was not made for Genesis CAN be used with Genesis—it just may take a little manual adjusting to get it to fit properly. Or sometimes a lot of manual adjusting…but it’s a good skill to learn because it greatly expands the variety of free and paid hair products you can use with Genesis once you know how. I’m actually working on a tutorial* that explains how to do this sort of thing, and will post the tutorial when it’s done (or at least done enough to be useful) but one method, briefly explained, is as follows:
Start with Genesis in the default position and pose. f you have the V4 and M4 Shapes for Genesis it may be helpful to dial up the shape corresponding to the figure that the hair was designed to work with…but that’s optional. Load the hair. Chances are, it’ll load too high or too low, but otherwise will be in the right position. Select the hair and go to the Parameters tab. Zoom in so you can see what’s going on. Adjust the y-position slider until the hair is in the right vertical position. You may need to adjust some other sliders as well—scale (or one or more of x-scale, y-scale, and z-scale) is a common one, especially if you’ve already reshaped your Genesis.
When it’s looking as close to perfect as you can get it, take a look at any morph fit sliders in the Parameters tab, and/or pose sliders in the Posing tab, to fine-tun the fit. Finally you’ll want to parent the hair to the Genesis figure’s head. There are several ways to do this—you can go to the Scene tab, and drag-and-drop the hair to the head (you’ll have to expand out Genesis by clicking the triangle next to it), or right-click the hair in the main viewing pane and select Change Parent. Make sure “Parent in Place” is selected. Now that your hair is parented, you should be able to move Genesis around and the hair will follow it!
Hope this is helpful, and feel free to ask if you have any more questions about it.
*I probably should add a disclaimer to this… I may be writing a tutorial, but please don’t mistake me for some kind of expert! Much of what I know on the subject, I learned quite recently from others on this very forum. The main reason I’m doing the tutorial is because I wanted to consolidate all this information in a single place. The tutorial will show up in the New User forum within a couple of weeks or so.