Im about to buy a new Laptop, which one should I buy?

With an accumulated total of $500 and $30 in Best Buy certificates I am looking to buy a nice laptop. From browsing the wide variety of laptops at Best Buy I have narrowed down my list to a couple of important specs. Within reason they can be modified but only in moderation. Here is the list:

• Full sized keyboard with no extra space between keys.
• Easy to click track pad.
• Decent picture quality
• No less than 2GB of RAM
• No less than 250GB of Hard Drive space - Be careful when looking at the Hard Drive space because a 500GB hard drive might not be the same space when looking at a different 500GB model; the reason being is that PC manufactures began to count 1 kilobyte as 1000 bytes versus the correct computer science model of 1 kilobyte as 1024 bytes (2^32). So a Hard Drive of 500GB could be really only 450GB of space, so pay attention to the small print.
• No less than an i3 processor
• Windows 7

I have an HP Slimline desktop that is perfect for my needs, but if I want to sit elsewhere in my house, I cant.

But If I move around with my laptop, I have a separate computer, with none of the files that my desktop computer has. So I have an idea of Networking the two computers together. The only problem is that my laptop will not have constant internet access, so possibly when I get home I can hook the laptop to the desktop and sync them together. Please give any helpful suggestions, as to what type of laptop I should buy or how to go about networking them together.