Any make but I will upgrade Wattage making sure it fits my pc.
I'd be careful in which manufacturer you choose. Cheap ones use low quality parts and cannot supply the wattage it was labelled as. General rule of thumb, stick to Corsair, Antec, XFX, Seasonic, OCZ, PC power and Cooling etc.
Depending on where you live some of these power supplies wont be available. Either way just use this existing thread to post your selected power supplies and we can evaluate them if they are good or bad. Anyways I would suggest moving up to 350-400 watts for your power supply, you can support future upgrades easier such as low powered video cards and installing additional hard drives etc.
What about 500W or would that be too much how far could I go in terms of wattage without too doing exrta work to the PC.
It does not really matter about the wattage, your computer will only draw what it needs from the power supply. If your computer uses 250 watts, and you get 1000 watt power supply. Only 250 will be used, makes no difference with 500 watts. Generally people do get a bit over what they need for power supplies but for your build you should just settle for 350 watts or 400 watts, UNLESS you plan on getting a new video card or adding in some other stuff.
I ended up purchasing a 500W OCZ CoreXStream 80PLUS Power Supply, for £39.99($63.64) and wristband.
I installed the PSU slowly as the SATA connector for the hard disk at the bottom as HP put the Hard Disk at the bottom of case once I managed to put cables in the machine started fine, however once I screwed in the case cover I accidentally sat on the keyboard and the purple connector is bent, but I found an old keyboard.
Must have been painful to have sat on the connector! Anyways how is the computer running? Everything works fine? Anyways good choice for the power supply, glad you went with a quality brand that will serve you for a long time!