Morrisons's Eat Smart Pork Sausages, the ones that say less than 3% fat are syn free on a red day. I like them better than regular sausages and they taste rather good cooked on a George Foreman Grill thing.
There are a few website for places that sell Syn free sausages on line but most have a minimum order and i could never justify spending that much on sausages!
With regards to the Quorn sausages, try some of the different flavours. I can't stand the regular ones but the flavoured ones are not too bad