Which Daihatsu for Motorway Ride Quality?


I'm about to say goodbye to my old car and am thinking of buying a new or nearly new Daihatsu or Perodua.

The thing is, I do a lot of motorway driving, and need reasonable comfort for trips of 100 to 300 miles, BEFORE my working day begins!

My wife has a 2002 YRV 1.3 and it is great, but after 200 miles is a little bit tiring, also it doesn't seem to do the promised miles to the gallon.

Would the new Sirion be OK for my type of driving, or is it too 'choppy' in it's ride quality? Are there other Daihatsus that give ride quality and MPG? Would the Perodua Kelisa do this as well, or am I really looking to buy the wrong car for my type of driving?