If you get the aftermarket ones, get the Beru one. I've had it for a while, no problems to report.
The cheap Intermotor one didn't give me hassle, but the contacts were all so small I assumed it wouldn't be getting a good spark. Sounds really anal and it probably didn't make a difference what so ever, but I felt better
ECP and GSF do the Beru ones I think? I know ECP definately do. They're about £30 and £8 I think. Not cheap, but not the stupid money for the genuine ones either, who are probably made by the same factory anyway
GSF stock what they can get sometimes thay get genuine caps but usually Beru which are good quality about halfway between genuine and Powertrain/Intermotor which are truly cheap and very nasty but they do work.
Arms generally are not so fussy - I get Valeo ones from my citroen man but the ECP/GSF ones are fine oyu just ned to remember to threadlock the bolts in place I think most people have had this experience - when mine did it I didn't fit theram and the cap it killed was a brand new genuin eitem
Cheers
Luke
Please call me Luke
1989 BX 16valve White 70k almost up to scratch