2007 Accord - looking for a comfy aftermarket seat cushion for traveling

I don't know if anyone can help me but I am once again traveling around the USA. I will be gone for several months. The last time I did this my butt was getting sore from the many hours of driving. Does anyone have any suggestions on some kind of aftermarket cushion that is available to lend some support. My seats in the car are just the stock cloth material.