In my opinion it will be enough power and as others have mentioned, you're going to want more RAM. In terms of other Intel I-series processors, I'm not sure how much better you're going to do. The most popular ones today like the i5-2500K and i7-2600K are rated at 95W. I couldn't find a quad-core I-series processor under 95W except for the i7-860S which is 82W and $360 (on newegg).
RAM doesn't draw too much power so don't worry about that and as long as you get 'standard' ram (under 1.5V and around 1333MHz) there's no risk in loading it up so basically you can fill up your mobo with as much as it can handle but sometimes too much is unnecessary. If you're using Windows the 32-bit version can only use 4GB of ram. Using more won't hurt, but 32-bit Windows can only use a max of 4GB. To use more than 4GB you need to use a 64-bit version. 4GB is a pretty standard amount in home-builds, 8GB is a decent upgrade, and 16GB is a common maximum but 16GB is overkill for most applications. RAM is sold in pairs and triplets and you're going to want the pairs. I don't know anything about your motherboard but the i5-2500K supports two channels of ram so stay away from packs of 3 and 6 sticks.