Here is the custom content I use.
Category A: Terrain Mods
BrisVegas (Brisbane) map by drunkapple
Erosion Control Mod Set by moganite
PEG Water Mod Brigantine by pegasus
Category B1: Transportation Mods
Network Addon Mod by NAM Team
Street Addon Mod by jplumbley
Rural Highway Mod by NAM Team
BRF Tunnel and Slope Mod by Frankie_Grove
Street Cul-de-Sac Mod by Qurlix
Hole Digging Lots by smoncrie
Modification of Edmonton's Region View Mod by CSGdesign
Category B2: Transportation Buildings
GLR Stations and Hubs by cogeo
SemiTransparent Train Stations by cogeo
Basic Ferry Pontoon by CSGdesign
Road Top Mass Transit by cogeo
Rural Train Station Pack by cogeo
Category C1: Commercial Growables
Low wealth commercial shops volume 1 by madhatter106
Category D1: Utilities - Power
Nexis Emergency Diesel Power by mrbisonm
PEG Geothermal Power Plant by pegasus
Small Solar Power Station by ixnayonthetimmay
SFBT Rural Power Supply by Andreas Roth
Category D3: Utilities - Waste
PEG CDK3 Garbage Docks by pegasus
Category E2: Industrial Ploppables
PEG CDK3 Capt Jacks Landing by pegasus
Category F: Aesthetic Ploppables
Bosham Church by mntoes
Category G: Agricultural Enhancements
Ir Placement Mod by fukuda
Rural Variety Pack by ihaka
Category H3: Civic Buildings - Educational
Small Community School House by CSGdesign
Category X: Gameplay mods
No fires or riots mod by bones1 (Note: I use this when rural areas are small and take it away for bigger cities)