RE: .243or.260or.280
Of the three you mention, the .260 Rem is what I would choose. It is flat-shooting and the recoil is minimal. It will take deer cleanly to any reasonable range.
The .243 Win is a bit light for deer. It will work, but is probably better in the hands of a skilled shot. The bullets just don't weigh enough for reliable penetration.
The .280 Rem is so close to the .30-06 in felt recoil that you can pretty much eliminate that fine round.
Here is another way of looking at this, with each cartridge being measured with a "normal" bullet weight used for deer:
.243 Win/100gr/7.25lb rifle/10.2 flbs recoil
.260 Rem/120gr/7.5lb rifle/11.0 flbs recoil
7mm-08/140gr/7.5lb rifle/13.5 flbs recoil
.280 Rem/140gr/8.0lb rifle/17.2 flbs recoil
.30-06/165gr/8.0lb rifle/20.1 flbs recoil
As you can see, the .260 more closely resembles a .243 in the recoil department, and it kills much more efficiently. The 7mm-08 is also on the light side and it, too, is an incredible deer round. The .280 is indeed closer to a .30-06 in terms of felt recoil.
Based on your criteria, the .260 Rem looks like the perfect choice. I have used that round on many animals, and seen it used on many more. Every animal fairly hit with it dies quickly and with minimal tracking. <img src=icon_smile_dead.gif border=0 align=middle>
Good Dogwork and Good Hunting