It possibly is, but there are some other concerns:
1) Our current Shutdown Controller is v2.4, and has many more features than v2.2, which you won't find anywhere unless you find a used one.
2) 1GB of ram will make shutdown to hibernate take quite some time, nearly twice as long as 512MB
You could try our PSU wattage calculator to get an idea of wattage needed for that setup. Everything won't be on the calculator there, but you can get a good idea of wattage needed.