From Clarkston you could go down Clarkston road, into Linn Park. Then follow the tarmac track to cathcart. From here follow signs to Pollock Park where you can pick up the cycle track that takes you to Paisley.
This is about 4 or 5 miles longer than cycling direct through Darnley etc but it is generally flat and interesting. Not too many neds but this will obviously depend on time of journey. Also the whole route is tarmac so can be ridden on a road bike.