I reckon the 91 and 222 would be 2 good Add ons for tsw4, the 91 available on ecml and 222 on the mml. The 2 units would add some variety to the 2 routes and the 91 is what loads of people wanted when ecml was announced.
Would prefer to see the 91, 90 and maybe an 88 in a UK AC loco pack. Just in time for the consist editor please