You almost make it sound as if you have a personal grudge against the Silver Fox guys.
They are pretty cool to deal with, as others have said before. Their A Class doesn't hold a candle to the IRM offering, that goes without saying.
But...
You want a C Class, even in NIR livery? No problem.
You want Mk3 coaching stock and EGV's? No problem.
You want a weedspray van to go with IRM's weedspray train? No problem.
Not my weathering, by the way, that was done by the very talented @Noel.
But the point is that even today, they are the only show for many RTR Irish items.
You've said that you're not a purist, that you'll have a silver A Class hauling Mk3 stock, so what's the problem with Silver Fox?