I’d go with a PC power supply. They’re cheap and strong. Probably stronger than anything you’d throw at it. The ones I’m working on today are running from a 650W Corsair ATX power supply. According the the sticker, it can give …
+3.3V 25A, 130W
+5V 25A, 130W
+12V 51A, 612W
The total peak load capacity is 650W.
612W is way better than that 80W.
I’m not saying that you have to buy this particular one. There’s nothing special about it. Get a cheap one, or salvage a mostly-working one from an old computer.
Look around for info on using it as a DC power source. The magic is jumpering the green wire in the main ATX plug to ground. Use any of the many pinouts to find which wires have the power you want.
I’ve seen some little adapters that break it out for you, with a power button. You don’t really need them. There is no dangerous output from the power supply. It’s all nice safe low voltages. Even if you mess up and short it, most recover gracefully with a power cycle.
The only real advantages I’d see with the Sparkfun power supply is that it’s ina pretty package, and gives outputs higher than 12V. If you don’t actually need 24V, don’t bother. Buy for what you need, not for what you might use someday. If the need comes up later, get a bigger one later.
When you learn a bit more, you could explore the fun of transformers, bridge rectifiers and voltage regulators. I thought about it, but it was easier to just jumper it and strip a few wires for outputs.
I’ve done this quite a bit over the years, recycling old weak power supplies to lower load applications like the Arduino.
I’m planning to make a higher current phone charger with it sometime in the future. It’s not very hard. Put 5V on the right pins, and a resistor between the others. Voila, a phone charger capable of (theoretically) 25A. The phones will only draw 2 or 3A, so I could charge a dozen if I wanted. It’d be better than the questionable quality chargers that you’d normally use.