Tomato Growers Supply Co.
Have a nice selection of all kinds of peppers.
How long seeds last depends on the seeds and how they are stored. They need to be kept dry Envelopes are better than plastic and cold preferably in the refrigerator. Warning: seeds can take over your refrigerator space. Some seeds have a long shelf life. My dill still germinated after 13 years. Beans 9 years, zucchini (not worth saving), lettuce 3 years. Most of my seeds lasted up to 5 years but only a few more than that.
I have pepper seeds that were still good after 5 years but most were good for at least 2 years.
Here's a link to how long seeds last.
https://extension.oregonstate.edu/garden ... seeds-last