You can run any retail ATX power supply in the 410. I would recommend getting a modular PSU so that you only connect the wires that you need and put the others away until they are needed. This will help with not getting a clutter of wires that block the air flow.

I went with a 650W modular, I have the Q6600, 2 DVD, 4 HDD and an nVidia 8800GTS in mine.

THank you for the quick responce. Will a 600W be fine?  What brand would you recomend?

A 600 would be fine. Just make sure the one you choose has the PCIe connectors for your video. I would look at Corsair, Thermaltake, OCZ, Antec. There are a lot of good ones to choose from.

I need to replace the PSU, and I need to open those cable management clips... how do I open them?

You grab them with pliers and twist then they break.  They are too old to flex open and closed as they become brittle.

A recommended power supply is EVGA SUPER NOVA 750B1 SERIES.  110-B1-0750-VR

B2 BQ G2 series DOES NOT WORK.

https://www.amazon.com/EVGA-SuperNOVA-Modular-Warranty-110-B1-0750-VR/dp/B00K85X23O