There is no such thing as a BIFL sheet. And I see you're looking for orange piping, not blue (as pictured). I would say get yourself some good quality sheets, and continue letting the wife do the custom piping. Unless you have a LOT of money to spend - then you can pay a seamstress to do it, or if you REALLY have a lot of dough, you could pay for a big enough lot the manufacturer will make a custom run just for you!

As for buying the BEST sheets possible, go for a high thread count. I would also recommend you look into a synthetic blend. People talk 100% natural fibers up, but it's hype (other than comfort). Synthetics last longer, so synthetic blends are typically the best compromise. Natural fibers DO have advantages, but long life is not among them.

Also, go easy on the bleach. Bleach is way harsh on fabric life. Depending on your water, you may benefit from adding washing soda. You could also look into bluing.