We have a 40+5×120 with 80 finishers. I'd have it 50+5 now, on TMR you don't need a full length trough and the straw blower would bed it up. Flip overs sound nice but I like our La Buvette Polystall better. Get them from IAE. They don't get mucky so don't need cleaning. On a green field I think I would have a central feed passage, only one lot of concrete rather than both sides, feed needs to be covered either way. Clean sweep troughs with no corners sound good too. I may modify ours one day.