I have family and colleagues who live in your part of the world, as well as Rottingdean and Telscombe Cliffs, lifelong. They dread it. Some are able to flex their day making sure they get to Rottingdean by 4, another one does the 4 mile loop via Ovingdean Village just to get a feeling of keep on...
It is horrendous. The jam all the way back to Roedean / Ovingdean roundabout starts building at 4.15pm. Then it’s stop start, snails pace all the way to Seaford.
100’s drivers get so fed up, they do a 4 mile loop via Ovingdean Village, back to Rottingdean, to simply avoid the first half mile...
But great suggestions by loads of posters in this thread about locating by the excellent rail links heading into Brighton, with other knowledgeable posts to avoid westbound car travel on the A27.
Having a blank canvas to choose from, with no family links to particular towns, gives the OP good...
Lewes (Prison, Earwig Corner, Culfail Tunnel, Ashcombe & Southerham roundabouts) is all hellish in both rush hours. Often travelling in the opposite direction to the masses, daily I see hundreds of cars with very fed up looking drivers, stuck in jams. Similarly, Polegate to Ashcombe Roundabout...