Quantity   Component name
2 × Mini-Box Y-PWR Load Sharing Controller This is a 20A load sharing module, which uses low loss mosfets to emulate ideal diodes. The core controller chips are quite cheap but are tiny sirface mount parts. This version by Mini-Box is the only complete package I could find. See http://www.mini-box.com/Y-PWR-Hot-Swap-Load-Sharing-Controller
3 × OSKJ QS-1212CBA-150W DC-DC Converter This is a well made step up/step down DC-DC converter, available on aliexpress for around $70. I've tested them to 100W and they barely get warm, plus they have connectorised outputs so it's easy to swap if one fails.
3 × ACS712ELCTR-20A Hall Effect Current Sensor 20A low loss current sensor on a breakout board. Dirt cheap on aliexpress.
1 × B3603 DC-DC Converter Programmable step down dc-dc converter with CC / CV settings and voltage/current display.
1 × Arduino Pro Mini All the awesomeness of Arduino, but smaller and more efficient. $3 on ebay for the win!
40 × Anderson PowerPole 15/30/45 Connector These are great connectors for all of the high current input power sources, I think I'll start using them in a lot more places too. Because they are genderless it's very easy to make up custom cables and it gives me a lot of flexability on the layout of my power supplies and battery boxes. Only downside is price, they are nearly $1 per pin so a complete connection pos/neg both sides is $4. It adds up quickly.
36 × Mini Tamiya Connector These are used for the output connections to all of my devices. Handles 4 amps or so and has a locking tab