GPS Module Recommendations for LEO CubeSat?

[blackwing-space]

We’re selecting a GPS receiver for a new PyCubed-based OBC we're building for LEO missions (~400–600 km). We need carrier-phase measurements for orbit determination and are exploring options across the $10–$700 range to understand what’s truly required vs. overkill.

Questions:

1. Which GPS/GNSS modules would you recommend for carrier-phase–capable LEO orbit determination?
2. Is L1-only sufficient, or is there a strong case for dual-frequency (L1 + L2/L5) at this mission class?
3. Any modules or chipsets you’d specifically avoid for spaceflight (radiation sensitivity, firmware issues, supply risk, etc.)?