You can get pepper seeds without restriction in Hawaii so far as I know. I presume you are talking about the capsicum peppers like bell or hot red peppers. The black pepper plants can grow in Hawaii in hot areas. This garden shop in Keaau has them.
http://www.store.hawaiiantropicalplants.com/ or you can grow them from seed.

I grow Hungarian Wax peppers really well here on the West side of Hawaii. The bush produces like crazy and I use them in stir fry's and with my ribs.....just the right about of heat.

Peppers seed are easy to get, store bought or from other sources.
Peppers grow very well here in Central Oahu.
Got 8 different types of Hot and 3 different No Hots. Hope to expand to more varieties this year.
I'm not a Chili head ! I just like Pepper plants. Nothing like seeing the fruit change colors.

you can order a couple kinds of peppers from University of Hawaii seed lab. Great deal, $1 a pack and 50 cents shipping for as many packs as you order. Looks like they're out of Hawaiian Chilies right now.

Also check out the other seeds available--papaya, eggplant, beans, and more.

Another option is to find a friend with the kind of chili you like. I have good luck planting the seeds fresh.

Here is a link that might be useful: UH seed labs