Make your own bridles, super easy.
Here's what I've done:
www.seabreeze.com.au/forums/Kitesurfing/Review/Bridles-replaced-twice-in-6-months-You don't need to do anything super fancy, just get some dyneema rope and make a couple of bowlines.
Just make sure they have the same size.
The original F-One pulleys are a crap. The edges are too sharp and they can rust with time if you don't look after them.
Now I'm using 20mm Orbit Ronstan Pulleys instead of the sheaveless blocks that I tried before.
www.ronstan.com/marine/product.asp?ProdNo=RF25109The Ronstan Orbits are the same size and way better. They will last forever.