RAM or processor will make no difference and there are no programmes that will physically 'increase' speed.
There are download managers that can make downloading more efficient by checking different servers but do not expect to be amazed at the difference.click here is one of the free better ones. Remeber they are not increasing the download speed, just finding the fastest servers.
Some 'speed up' programmes claim to speed up your surfing by caching or remembering pages that you have visited or trying to guess which page you will got to. The problem with these is that your temp file cache becomes enormous and guessing where someone will go next is truly X-Files territory.
The only way to increase your speed is to go broadband...if you can.