Sterling - What are using the car for...
If for the road or off road then socks are best - get the unifilter ones and use with ram tubes... If your engine is tuned properly you will not have any backfires and will not set the socks on fire with ram tubes... (I have sat in a buggy that was not tuned properly and it had a habit of settign its unifilter elements on fire right behind our heads, but after tuning and putting socks on - it never did it again...)
Mesh are only good for a racetrack and will stop rocks getting in.. They will still allow dust and dirt and will lead to early engine rebuilds..
K&Ns are supposedly better flowing for ultimate flow, however in a Mk2 you do not have enough room to run the taller ones to allow ram tubes inside them with enough clearance and the ram tubes will make the car much better and driveable than without.... So use socks on ram tubes and keep them clean and do not over oil...
If you are talking about GDUBS twin carbs and cam setup which was tuned well, he always used socks and never had an issue...