Here is a guide to the available files and options.

Enhanced Solitude (LE, SSE) - The city overhaul

Enhanced Solitude Expansion (SSE) - So you can use Enhanced Solitude and Solitude Expansion at the same time - Requires Solitude Expansion

Enhanced Solitude Buildings (LE, SSE) - The retexture work for vanilla Solitude - Standalone for vanilla.

Enhanced Ships of Solitude (LE, SSE) - Adds new ship models to Solitude docks - Contains LODs - Standalone

Enhanced Solitude Cherry Trees (LE, SSE) - Adds more cherry trees to Solitude Entrance

Solitude main wall texture Brown (LE, SSE) -  From Tamriel Reloaded HD - Contains LODs

Solitude main wall texture Dark grey (LE, SSE) -  From Osmodious - Contains LODs

Blue Palace Terrace for Dev Aveza (LE, SSE)  - So you can use both mods together - Requires BPT and DAA

Blue Palace Terrace for Palaces and Castles Enhanced (LE, SSE) - Requires PCE

Blue Palace Terrace for Dev Aveza and Palaces and Castles Enhanced (LE, SSE) - Requires BPT, DAA and PCE

Bells of Skyrim (LE,SSE) - Patch available, moves the bell tower in Solitude to behind Books of Skyrim

JK Skyrim AIO (SSE) - So you can use Enhanced Solitude with JK Skyrim AIO SolitudeWorld Removed

LotD (LE, SSE) - Compatibility patch for Enhanced Solitude and LoTD

Enhanced Solitude DoS Compatibility File (SSE) - DawnOfSkyrim Directors cut with the SolitudeWorld removed.