Ok, I got tired of reading everything about halfway through, but I thought I'd give my two cents.
I'm going into my last year of college as a Mechanical Engineer (i noticed it mentioned somewhere, not sure if that's what you're going into or someone else), and I just ordered a laptop (my first). I was originally looking at dell, but because I didn't know other good brands existed. I will be using that "engineering stuff" heavily, including Pro/Engineer, AutoCAD, IDEAS, among many others. I will also plan to do a bit of gaming. After doing all my research for several weeks, I went with what you see in my sig below for under $1800 (i know price was an issue for you, as it was for me, and i was planning on limiting to $1500, but thought the upgrade is worth it to make it last longer).
If you would prefer to stick with Dell, my advice is either take as much memory as you can for free, or get only one stick, in both cases upgrade on your own as it will save you A LOT of money. Also, they are right about the performance boost with the higher speed hard drives, but I haven't found it cost efficient enough to spend an extra $100 to go from 5400 to 7200 instead of $15 from 4200 to 5400. My opinion is that 5400 is fast enough. However it seems I get attacked every time I say that, but that's why I say it's my opinion. Also, if you plan to purchase from dell, do check the coupons thread to save some money.