Hey PKR,
I have not used the 550 watt PSU in your link (but I did look at the specs)...
Technically it should work - more than enough power to run a 176 watt Pelt (12 x 25 = 300 watts theoretical max). some people/power supplies run into trouble when they try to pull a heavy load on the 12 v rail without any load on the other rails - specifically the 5 v rail. Most PC switching power supplies have the 12 v and 5v rails sharing a common regulator circuit. They are designed for moderate pull on both rails but can loose regulation and not perform well when loaded out of ballance.
If you do go with a big generic PSU, I would put a couple large 5 ohm power resistors across the 5 v rail to load it up with a couple amps to help maintain regulation on the 12 v rail.
I assume you Pelt is a 15 V-max unit...
Personally, I use the MeanWell - it's a little more money but it's solid, compact, you don't have to "wonder" whether it will work, and the output is easily adjustable (+/- 2 volts) so you can dial in your Pelts sweet spot for cooling.
Good luck,