Oh yeah, also take Othello Road for the final stretch into Hope, and do check out the majorly cool tunnels if you've never seen them.
Don't be too worried about the Coquihalla, you skip the entire Kamloops to Merritt section on 5A, and out of Merritt you actually skip a big chunk of the climb on Coldwater Road before joining the main highway 5. Coldwater is hilly with wasted climbing as well as needed elevation gain, but at least it's very pretty and non-highway. I would imagine you've heard that there's a few mild uphill sections on the route already and aren't terribly put off by the idea? No
If the Fraser Canyon is interesting, check out Kamloops to Merritt on 5A, then Hwy 8 to Spences Bridge. My choice over Hwy 1