Welcome KJT2004
Doopers are great cars as for the extra power im sure that 'Lohen.co.uk' do a chip and few upgrades as they have a Dooper clubman that is a bit warmed up...or speak to the guys at '1320'

Headlamps...not too sure about the 'Fried egg' look best to have a look around the likes of minitorque.com im sure you had the option of ordering the lights with clear indicators from factory.

MINI do a aero kit from Factory that has a black grille ..
centre arm rest you may find a damaged car in the breakers with one on! theyre pretty easy to fit if you have all the brackets etc try 'minimatt.co.uk' or even e bay as many breakers advertise on there too