I did a similar trip in my Jeep in June 2007. Bring your tent. The pacific coast is loaded with RV parks and campgrounds and every one I stayed at was at least very good quality and many were absolutely gorgeous.
Dont ride at night (cows on the road) and keep an eye out for unsigned speedbumps (topes) on the highway before you enter a town. The sneakiest ones tend to precede auto mechanics' shops interestingly enough. Pinches topes.
The road along the coast is a dream road. I was giggling all day long through the twisties and I was on four wheels!
Puetro Escondido is fantastic little spot with many secluded coves with beautiful beaches and lovely people. The best fish tacos I have ever had.
Mazatlan you can skip. There is a cool 'old town' area and nice beaches but in my opinion not worth enduring the traffic and new part of town (mr. frog's, etc).
Its an incredible ride. Once the sun starts to go down you just turn off the highway. Wherever you are there is sure to be a little beach town, likely with a welcoming place for you to camp and some incredible food to fuel your journey.