Yes, all you need is the appropriate adaptor to take you to 203mm,
BUT - Do you need it? for a road tourer, would suggest not.
The fork will have been designed for a 160mm rotor, and putting anything bigger could lead to frame / fork failure, and with the rear, you may also have issues with any more than 160mm, and also with the rack / mudguard mounting.
Larger discs are only really needed for Mountian Biking, and not on the road. 203mm are normally only use on the front, and then for full on DH, North Shore or AM bikes , on an XC bike, 180/160 or 160/160 are normally used.
Would stick with the rotors you have, as if the cailpers are correctly set up, you should not need anymore braking power to stop a road tourer.
For the BB7's upgrading from BB5's, there should be no issues with a straight swap of these.