Question Gridboss with 100A service and direct sunlight - repost

Repost because previous message disappeared

I only have a 100 Amp service to my house. Can I put a 100 amp breaker in the Gridboss instead of the 200 amp Eaton breaker that is listed in the manual and use this as a service entrance from my meter? If not, am I correct that I could run a line from my existing main breaker into the gridboss lugs without using the 200 amp Eaton breaker? Do I need to upgrade my service to 200 amps in order to use the gridboss? 

My meter is on the south side of my house. I could mount the Gridboss on the south-facing wall or the east-facing wall. The manual says not to mount it in direct sun. Could a custom-made cover or one of the commercially available inverter covers be used to sufficiently protect the gridboss from direct sunlight?