Regarding links to snakes for sale on different sites, I don't think there's an issue since you aren't doing it for advertisement purposes. In the rules guide, this is the info I found regarding site links.

12. Links or text with the purpose of recruiting members to competing sites are not allowed. Linking to other sources for the purposes of sharing something unavailable at BP.net and/or for the purposes of promoting reasonable and appropriate discussion are allowed. However, links to other forums for the purposes of slamming the site, an individual, or other inflammatory action are not allowed.

13. Respect bandwidth, copyrights, and ownership. Do not "hot-link" images from other websites or post copyrighted material without the express, written permission of the owner.

Since you're not doing any of that, I think it should be fine. If I'm wrong, I'd like it if someone corrected me. If you want to wait for official word, feel free to just PM me.