What speedring for Einstien that fits

hi
I'm planning to buy two Einstien 640 heads, the only thing stopping me form doing so is that i heard that  the fingers fail and drop soft boxes  and a number of Einstein users have had issues keeping large Octas and soft boxes attached to the light due to the weakness of Baclar system,   so i need your help if there is any solution for this , do u recommend any third party speed ring that fits tightly to Einstien apart from Kacey

--
Egami
http://www.flickr.com/photos/sudanesepixel