If you do go for the rewire - just make sure you write a specification for what you want now and possible future upgrades.
Talk it through with sparks who come to quote
Think about CAT 5 or 6 to rooms with TV's, aerial cables, boiler control wiring, mains smoke and heat alarms, outside lights and power .....
Adding things later could be major upheaval, more plastering and decorating and higher costs
Rewires, new circuits and changes in bathrooms fall under Part P of the building regs - so make sure the person doing the work provides electrical certificates AND Part P certificates too.