It sounds like you have a good idea of the fittings you need for your water-cooling setup. You're correct that you'll need 1/4" fittings to match the inner diameter of your 12mm tubing.
For the radiator, you'll need 3 90-degree fittings to connect the tubing to the radiator's inlet and outlet ports. For the block, you'll need 2 fittings to connect the tubing to the inlet and outlet ports of the MX1 Plus.
For the reservoir, you'll need a stopper fitting that matches the port size of your Pacific D-32 or D22. It's a good idea to check the specifications of your reservoir to confirm the size of the port before purchasing the fitting.
Finally, you'll need regular compression fittings to connect the tubing between components and make turns as necessary. You can purchase these in packs of 6 or more depending on your needs and budget.
When selecting fittings, make sure to choose ones that match the material of your components (e.g., brass fittings for brass components) to avoid corrosion and leaks. It's also a good idea to purchase fittings from a reputable manufacturer to ensure quality and compatibility with your components.
