The east side always seems most straightforward to me. You have the advantage of relatively low ground, and lots of diversion airfields in case of bad weather. I just drew a line direct from Perth to Earls Colne Airfield, then direct Mayfield VOR and that seemed quite practical. From there you have an easy run to anywhere on the south coast, and the incraese in time en-route at around 110kt, compared to a direct track to Shoreham, would be 10-12 mins.
MJ
