One idea is to meander your way through wineries [which are primarily off/near Highway 99W which roughly parallels the interstate that runs the entire west coast. Head south on 99W to Corvallis; then head west to the coast from there to Newport. Newport is large enough that it has a selection of lodging and restaurants; a couple of business areas that are just touristy enough to be shy of annoying [Nye Beach and/or the old bay front]. It is central enough that you can take day trips north or south and not have to repack and move every night.
If you wanted to, you could spend a night or two there, then move your base down to Yachats which is quite small -- good if you like a quieter atmosphere.
Another option is to head west from Portland to the Cannon Beach area before meandering down the coast to Florence. You could divide the coast part into two locales: Cannon Beach for the first part, then Newport/Yachats for the second part. You could do the length in one site seeing day but you would be spending a lot of time in a car.
The old bayfront in Florence is fun for poking around -- shops, restaurants, coffee shops. But I would opt for staying in a town where you can be perched right on the ocean front.
It terms of places to stay, are you looking for a place to lay your head for the night that is clean and comfy? Or you want a place to stay that says WOW?