@jjlee32, adding to @stelian's post, if I understand correctly, you want to power the following:
12V inductive loads
- 4 solenoids, 0.3A each (max total 1.2A)
- 2 pumps, 5A each??, max total 5.3A??
12V (???) resistive load
- Heater, ??? A
- Particle device, max total 0.5A
Getting a more detailed set of load characteristics would be helpful.
The inductive loads will require surge current capability while the resistive load less so. Since it looks like you are using an AC supply, you may want to look at a ATX (PC) power supply. You can get smaller versions like this one from Aliexpress for example. These types of supply provide plenty of current and lots of protection.
You will need to design your control hardware (power FETs, etc) carefully when driving your inductive loads so as to protect your hardware from surges and flyback voltages. Your wiring will need to be sized to the current demands as well.