Was thinking about fitting a hid kit but I've read that it was illegal on the mk1 octavia vrs is this true?if so what would be the best replacement bulb for the main beam?

As explained here;
http://webarchive.nationalarchives.gov.uk/20120606172804/http:/assets.dft.gov.uk/publications/dft-information-sheets/aftermarket-hid-headlamps.pdf

You can get more powerful bulbs, OSRAM Night Breaker, Philips Crystal Vision. Plenty of topics on these forums about headlight bulbs, here is a link to some topics: https://www.google.co.uk/search?q=nightbrakers+and+philips+120%25&ie=utf-8&oe=utf-8&gws_rd=cr&ei=vMxYVdPlD6Sc7gaBmoHYAw#safe=off&q=best+headlight+bulb+site:www.briskoda.net

Night breakers have better longevity than the philips i believe - many replaced after 12months, NB's still perfect after 2+ yrs.. and i use dipped beams all the time for improved visibilty to the other drivers..