word processing, spreadsheets, internet, email
Graphics Card
The ATI Mobility Radeon HD 4570/NVIDIA GeForce 310M are both mid to high end dedicated graphics cards for laptops. There are many cheaper dedicated mobile graphics cards available that are still decent.
However, you really don't need dedicated graphics for the tasks you listed. It's overkill. It will cost more and give you poor battery life. It will not give you better performance for those tasks. It just isn't worth it unless you have some specific needs for it that you have not mentioned.
Processor
If I were you, I would trade off the price of the dedicated card and apply that towards the best processor I could afford. If speed is very important, then go for the i5 520M over the i5 430M or get something even better than the i5 520.
RAM
1066 DDR3 RAM is still very fast, probably good enough. I don't think you would really notice any difference in those ram speeds.
Inspection and Comparison
I can't stress enough the importance of actually trying out the keyboard in a store. In a picture most keyboards look alright, but when you try them out, some are just plain awful. Some keyboards flex and some keys don't push correctly. Also, some laptops have a slanted keyboard which you might find you like better.
Look at the layout of the ports. Sometimes usb ports are placed in nearly unusable positions - hard to believe, but true.
Check the screens out. See what is the most comfortable size compromise for viewing and carrying. Do you like glossy, bright, high color reflective screens or matte screens that won't reflect all the light fixtures?
Check the battery size out. The really long lasting batteries often protruded significantly out of the bottom of the laptop. Some people like this as it makes the keyboard more slanted, but it makes travel more difficult.
Optical drives vary too. Some people absolutely love slot loading drives; others complain that they don't work well or that they scratch discs. (I haven't heard a lot of complaints about slot loading CD drives in vehicles though...)
See if it feels solid and durable; lift it up, test the screen hinge, etc.
Compare your observations and the features of the various laptops on display.
As for the laptops you mentioned:
I've tried the Dell Studio 15"; it's not bad but wasn't that great either. I've seen some Sony Vaios before, but they were expensive for what you get and only moderately sturdy. I'm not familiar with the F Series. I never cared for Asus before I actually tried one out. The models I tried were very affordable and sturdy, but have more graphics power than you would need or want. You may very well find new brands that you like.
Walmart, Sam's club, Best Buy, etc. all have a decent selection of laptops on display that you can try out. I used to only like HP and Dell, but I found that some of the Asus and Lenovo laptops are very nice also. By the way, just because I recommend trying out a laptop in a store, doesn't mean I recommend buying it there.
Final Recommendation
Really, picking out a laptop is much more difficult than choosing a desktop. Personal preference plays a much greater role here. You may not be nearly as picky as I, but I would still heavily recommend that you try some out in a store (to see what brands you like). Also, unless you know you need it, drop the dedicated graphics requirement.