Our route South this Winter will be via Peuorto Vallarta.
In past Years We have gone via The route that You have indicated.
There are actually so many decent routes these days .
Tala to get over to 80 and Villa Corona. Chimulco is a good place to stop for a few Days and relax.
Then You have a couple of choices to get down to the Coast.
The Toll Highway Through To Colima ,Manzanillo ...Melaque is certainly the easiest .
You can also go straight down 80 ..A Very scenic and winding Road but quite doable if You take Your Time!
We came up that way last Spring! I think coming Up is easier than going down!