I'm like these vinyl labels, in this size, but ideally could get this in a brown "paper sack" color. Is this option available? And, at what price?

We currently only offer our Weatherproof Vinyl for Laser material in white. However, I will be happy to forward your request to our Product Development Team to review for future consideration. In the meantime, we do offer custom tinting options on several of our materials, including the Weatherproof Polyester Laser. You can view these options and pricing at the link below. https://www.onlinelabels.com/custom-color-labels.aspx

can you write on these with permanent marker?

The Weatherproof Vinyl for Laser works best in a laser printer. It is not coated to absorb liquid ink so regular ball point pens are not recommended, however permanent markers like Sharpies could potentially be used. You are welcome to visit the link below to request free sample sheets for testing. https://www.onlinelabels.com/samples