Go grab a job at a corporate tech place, and then laptop bags will roll in like candy.

Doing some spring cleaning, and have come across several branded bags from my past of various shapes and sizes. Next time I have them all out prior to a thrift store run, I'll take a look at which ones might meet your needs. My own tech yard sale of sorts will likely be in mid May.

If you're laptop is near the same size as any Apple systems, can definitely recommend some places that will let you assemble exactly what you need. I may be ordering one custom again here soon once I stabilize my tech needs for this year.