Internet download speed is all to do with your ISP, you can't change it with hardware, you can but I don't think there'd be any point in setting up your own communications company. And you need a good Hard Disk Drive, memory is your RAM, I would of thought if you sort of skimped a bit on some other parts, you could get maybe a 250GB - 300GB HDD and not notice a huge increase in your price, especially if you don't mind too much about speed.