You can get a look around both parks in 1 day but dont expect to see everything. Rides like Peter Pan and Pirates get insanely long lines so get them done early. I would probably hope to Hollywood Studios in the middle of the day when Disneyland Park is at its peak. Just do the big rides at HS (TOT, Aerosmith, Crush's Coaster and the studio tour) and head back to DLP for the arvo/everning.
I stayed at Disney's Newport Bay Club and its 10 min walk to the parks through Disney Village. Its a bit cheaper than Disneyland Hotel and Disney Hotel New York, you also have Disney's Sequoia Lodge which is cheaper again and walking distance.
On another note, at Disney Village I highly recomend Annette's Diner for a good burger and watching the kids deliver food up and down stairs on roller skates I almost worth the price alone.
A word of warning, EVERYTHING at Disneyland Paris is expencive. Food boarders on insane and if you need to save money head out to Maccas in the Disney Village if on a budget.