Hi, I believe the most common option was Bosch lights. Expect to pay £10 ish each for them, keep checking ebay, car boots and stuff. You never know where they will turn up.
If you buy some original 70's lights they may come with 48W British Prefocused bulbs. You can upgrade these to halogen 55w, but with a BPF base. See link http://www.classic-spares-electrical.com/phdi/p1.nsf/supppages/bby?opendocument&part=4" onclick="window.open(this.href);return false;
I have a set of Lumax D1's on mine, which didn't cost a fortune.
I picked up a fog light that has a rheostat control so that you can adjust the brightness of it,only payed £5 for it at a local classic car show.In the past Ive wired spots direct to the battery with an inline fuse with heavy cable which I know isnt the right way to do it.Ive read elsewhere that I should use a relay in the circuit,could someone please post up a simple diagram and tell me where I can get hold of a relay that is suitable. Thanks in advance. Chris