Well, I'm using Army Painter as a clear primer and sealer before glossing with Future Shine. That's about as durable as it gets without using China-grade, illegal paints.
I'm really not the one to ask though, since I don't usually keep the Preds I paint. The couple I've done for myself get posed once and left alone. I'd handle them more carefully than the average collector might anyway. Model kits from the good 'ol day were usually fragile, and I treat everything with my paint on it like a model kit.