Can't bring up your link ....
Some words of caution:
Taking off the existing bath taps might be very difficult and depending on how they have been installed, might need to you install isolating valaves (unless already done), and also to cut off a length of the piping.
This length will need to be replaced, perhaps with flexible lengths.
Getting into the right position in the possible very limited space beneath the taps of your bath will be very difficult and might make it practically impossible to tighten nuts adequately.
And lastly... couldn't see the link, but some B&Q mixer taps are very difficult to adjust in use - from experience at the BIL's house,they come on either red hot or freezing but won't give a steady flow at one temp.
I have found Bristan mixers excellent for this - I am sure many other excellent brands are available.