What kinds of apples are suited to be filled with cranberries and baked?
In his in depth review of pie apples, Kenji Alt points out:


  Well, there's another thing that acid does: it strengthens pectin, the
  cement-like glue that holds together the cells of fruit. So looking at
  this arranged spectrum of apples is actually a pretty good indication
  of how well each fruit is going to hold up during baking. The further
  right along the browning scale, the firmer the apple should be in the
  finished pie.


This same affect will apply to baking apples filled with cranberries:  you want an acidic apple, as they are going to hold their shape best when baked.

While I don't know the varieties available to you, he points out that the more acid the apple, the more slowly it browns when cut:


  [A]cid can inhibit the browning oxidation reactions that take place in
  fruit flesh when it is exposed to the air. For this same reason, cooks
  will store trimmed artichokes in acidulated water—it prevents
  browning.


The slowest browning, and most acidic of the US apple varieties he tested was Granny Smith.  This Whole Foods recipe for cranberry and almond stuffed apples concurs.



This goal of having a sweeter apple to counter-balance the cranberry filling is at odds with needing a more acidic apple to contrast with the cranberries.

Instead, you may be better served by adding sugar to the cranberry filling.  Since both cranberries and apples are assertive flavors, they will stand up very well to a sweet filling.



Time and temperature for apples are pretty flexible.  A survey of baked apple recipes shows options from 325 F (160 C) for about 45 minute to an hour to 400 F (205 C) for 15 minutes.  The important thing is to take them out when they have become tender when tested by pushing a knife point through the body.