Capri XR@ Turgo ignition leads

I've just bought a 1992 SC Capri XR2 turbo.
Does nay one know if I can use non original HT leads?
The local auto shop tried to sell me Bosch leads as per their catalogue but they don't look right. The originals have a very long rubber boot with seal on the spark plug end. I'm not sure if this is really needed to be able to attach to the plug properly.
I would appreciate any advise and also if anyon eknows any leads from other cars that might fit.
Thanks