St. Cuthbert: Helm
Pelor: Lathander
Wee Jas: Kelemvor
Kord: Tempus
Erythnul: Bane
I placed Cauldron in the Alamir Mountains, northeast of Almraiven in Calimshan (on the FRCS map, right about where the "M" in "Mountains" points). There's a map in the second post of the Shackled City Story Hour thread linked in my sig. Almraiven stood in for Sasserine.
In my view, a high mountain city built on the edge a volcano and atop ancient ruins is just asking to be draped in Incan/Mayan architecture. Stick it near the Lake of Steam. Greenwood's been designing the Border Kingdoms on WotC's site now anyways.
I placed it south of Tashluta and in the mountain ranges West of Halruua. My exact location is....
150 miles SW of Talath Pass and 260 miles west of Halarahh.
For Temples...
Church of St. Cuthbert - The Bastion of Helm (Helm)
Cathedral of Wee Jas - The Cathedral of the Dead (Kelemvor) **** This is a cover for a sect of Myrkul Worshippers led by Embril Aloustinai.
Temple of Lordly Might - switched Kord to Tempus
Shrine of Pelor - Shrine of the Sun (Lathander)
For Organizations...
The Striders of Fharlanghn became another Harper Cell.
The Ebon Triad - stayed the same but the gods were switched to Malar (Erythnuul), Shar (Vecna), Bane (Hextor)
The "official" location is on the north-eastern section of the Chultan peninsula, south of the Lake of Steam. My own conversion placed it in the Vilhon Reach, in the section of Mountains between Hlondath and Chondath.
My own conversions for the deities:
Wee Jas = Jergal
Pelor = Lathander
St Cuthburt = Tyr
Kord = Nobanion
The Age of Worms conversion guide I did for Paizo impliciltly acts as a conversion guide for part of Shackled City as well. As I put the Spire of Long Shadows (mentioned on the Shackled City map) in the Chultengar (eastern reaches of Jungles of Chult), you can derive a location for Cauldron as atop the mountain passes from Samarach to Tashluta.
Additional information on converting the Ebon Triad is given in those guides as well.