|"I am more trying to find out what ones are suitable in stock ones"|
Power supplies come in different form factors, they're not a one-size-fits-all thing. Standard ATX is the most common type; like the Corsair 430W that I linked to in my other response, but there's also micro-ATX, TFX, ITX, & a few others. You'll have to figure out which type you need. All computers use one of these types but some manufacturers (Dell, HP, etc) occasionally use proprietary wiring.
As far as wattage goes, there should enough to power all the components + extra for possible upgrades + extra for a safety buffer. The hardware components will only consume as much power as they need so don't worry that you can have too much wattage...not having enough is when you should worry. For example, if your system is calculated at 200W, a 220W PSU doesn't allow for either upgrades or safety. It would hold up for a while but since it would be running at almost max capacity, it would probably die an early death. A 400-500W unit would allow plenty of breathing room.
No matter which type you need, you should still make sure it has a single +12v rail, active PFC, 80 plus certified, good warranty.