Got my A1181 09' MacBook 5,2 running a 500GB SSD, 4GB Ram, and pushed it from the max OS of El Capitan to Mojave with a patched install USB I put together (:
Hdd Connector Flex Cable For Apple Macbook A1181 13.3" Laptop Sata Ssd Hard Drive Adapter Wire 820-1965-a - Pc Hardware Cables & Adapters - AliExpress
320GB 2.5" SATA 5400RPM MacBook Pro Hard Drive Upgrade
Apple Macbook A1181 Laptop Hard Drive Replacement - LaptopHDS.com
Lion 10.7 SSD solid State Drive 2.5" 250GB 256GB - Macbook Pro a1181 a1211 a1176 887276057484 | eBay
1TB 500GB SSD Upgrade for A1342 A1181 A1260 A1286 2008 2009 Macbook Pro 13" 15" | eBay
Throwing $85 Worth of Upgrades at an Ancient MacBook: Apple MacBook A1181 Complete Upgrade Guide - YouTube
MacBook A1181 Battery, RAM, and SSD Hard Drive Upgrade Repair - YouTube