As has been said before - spend the money on the optics and you won't get better than a Zeiss 6x42, or Svarovski or Schmidt and Bender of the same power. Will do every thing you ever want out of a scope - plenty powerful enough to take any deer out to 250 yds, but equally not too powerful when that buck jumps ut 20yds in front of you and in low light will be very bright. OK poss not the scope to be choosing which eye of a rabbit you are going to try and put a bullet through at 300 yds, but with my 6x42 have happily shot foxes with 243 out to 200 yds and neve felt under scoped.
Of the above three brands - probably interchageable and depends one waht you can get a deal on.
Reticle is important - Go for a German No 4 - thick out posts - useful in low light, and fine centre wires (and make sure they are quite fine). I would steer away from post reticles or large centre dots as whist fine on short range targets, tend to cover up a bit too much on longer range stuff.
Don't scimp on scope mounts though - probably the biggest source of problems in a rifle. If you don't know how to mount a scope properly then get the help of somebody who does to help you do it correctly.
Most guys who use variables stick them at 6 power and leave them there, and you pay double the price for a variable.
Wetherby's have long had a reputation of being good solid accurate rifles.
Choosing a rifle is a personal thing - go with what feels comfortable and natural to you - if it feels correct and like an extension of yourself then thats the right rifle for you.
I don't think you will have any bother with your chosen package.
Calibre - 243, 270, 6.5x55, 308, 30-06 - all will go bang and all will kill deer just as dead out to 200 yards. OK one might shoot 1 inch flatter, kick a bit harder and knock a beast over skin it, dress it out and carry it back to the larder for you, whilst with another the deer may run 20 or even 60 yards before falling dead, but at the end of the day all will get the job done on any UK deer species, provide you put the bullet in the correct place. And if you didn't know which calibre you were shooting, I would suspect most of s would have quite a hard job in telling one from another in the field.