Front speaker replace R53 (adaptors etc)

My front speakers have finally blown and i need to replace them.
Do i just buy a pair of adaptors and then purchase any 6" speakers?
If so could i run into the problem of the rear of the speaker (magnet) not fitting in as i noticed the window runner is close by?

I just need a recommendation for a fairly decent set from around 150 quid to about 200.
If i go component will the new tweeters sit in the same position?