demon tweeks is great if you want to spend silly money to race the mcdonalds drive-thru circuits.
you'll need a 6point FIA approved roll cage for the bravo, no one sells one that i know of, so you'll need ot have one fabricated. that isnt unusual, and it often costs less than buying an of the shelf omp or sparco option. where can you get it done? ask your local motorsport lovers. (they'll know all the best places to go -most of them will have custom cages).
suspension is available from all over the place. i assume you'll be wanting adjustable coilovers like this:
http://www.potn.co.uk/p1269161.htm
i dont know what "etc etc" is so i cant help if you dont even know what you want, but google is your friend when searching.
you'll definately need a bucket seat with harness. the bravo seat subframes are available from sparco, or you can fit a cheaper universal one same as on any car.
if you feel the need for a front upper strut brace, you can get them all over for £80. not sure about rear upper or front lower, but bravo chassis is very rigid including the suspension turrets so imo there is no need.
have fun. the bravo chassis is very capable, imo it would make a good track car (defo better than a mk3 golf gti for example)