Hi,
My name is Jary, a ID firm will sure discuss throught the design and advise on some part and show you the stuff eg. Sink and toilet bowl. We will also try work thing between your budget but first if you got to get a resales flat, I suggest that you take a look at the house that you buying then decide on what you wish to renovate. best if you can bring a ID designer down with you so that they can take a look at the flat and advise you.
Jary