If you want hissers just go to your local pet store and go to the feeding section, The containers are very cheap and come with two hissing cockroaches, be careful as some may arrive pregnant. I've had my two female hissers for about a year now and they're always together on their little log I gave them, If you you're not breeding them and want a small number then just get a large pet carrier cage, its perfect for them!
TDLR
1. Go to petshop and look for roaches near the food section
2. Buy large pet carrier for them to live in
3. Buy squirt bottle
4. Buy cocconut grounds (this is the dirt on which they will on, they love it!)
5. Learn about what and what not to feed them and give them ground cat food or dog food with every meal.
6. Give them some hiding spots like a log (my roaches just love to sit on their log)
7. Mist the cage everyday so that it remains humid, they like it humid
8. Clean cage whenever you feel like its dirty
9. Have fun with your hissers!