That page is a mess. I use
http://www.shamsports.com/capulator and would recommend everyone else does.
Declining every option, waiving every non-guaranteed player, and renouncing their rights* puts the Jazz at $32.7 million in capspace by my estimation (we don’t actually know what the cap will be heading into the offseason, although the number I’ve heard most projected is $109 million). That amount would likely be a max slot (for a player of up to 9 years of experience) or could absorb Conley outright.
If you can toss any guarantees salary in the deal, that would become spendable capspace. If you put Exum in the deal and stretch Korver, that gives the Jazz close to $15 million in cap space AFTER the trade. They would also still have the room exception of ~$4 million a year (which cannot be combined with capspace to make a larger figure).
*That means no Favors, Rubio, Neto, Thabo, Udoh, and whoever else I’m forgetting.