Should I get a memory foam or gel seat?

I’d recommend a gel saddle over memory foam for your needs.

Gel saddles conform to your body shape, absorb vibrations, and provide better pressure relief, which is crucial given your tailbone history and the rough terrain on your route.
Memory foam works well for short rides but tends to compress over time and may not provide enough support for your 6.7-mile commute.
Additional Tips:
✔ Look for a saddle with a center cutout to reduce tailbone pressure.
✔ Consider a suspension seat post or a gel cover for extra shock absorption.
✔ Proper bike fit is key—adjusting saddle height and tilt can significantly improve comfort.
✔ Padded cycling shorts can add extra cushioning.

For your situation, a high-quality gel saddle with ergonomic design would be the best investment for long-term comfort. 🚴‍♂️