Hi. I'm on my 3rd laptop - I use desktop PCs as well (I keep my old ones so I can try out my software on different OS's, and because they're not worth much, and are still useful).
Laptops are all about compromises, so your choice has to be based on your priorities.
1. screen size. bigger is nice, but it means the whole thing is bigger, so is less convenient to carry around. consider a smaller box and a flat screen where you use it most.
2. speed/power - means shorter battery life. even if you want to use an invertor to run off a car/boat/caravan battery, you may find the current is excessive. Some also have high surges, which can cause problems.
High power also means HOT. ventilation slots in the bottom of the case means don't use it on your lap (or anywhere but a hard surface).
3. if possible, try out the keyboard and mouse (stick/pad..). make sure you get on with it! consider an external keyboard or numeric keypad where you use it most.
4. if you're on the move, the ones with a mains input save you carrying a separate power supply, but means it's heavier.
5. I used to recommend Toshiba, but even they have had problems (e.g. the sat. pro 6100 power 'issue'). I currently have a Fuji/Siemens, which seems to be good value for money.
6. Get the biggest memory option you can afford, preferably as one module. They often have only two 'slots', so you may have to remove one when you want to add some later.
7. If you record DVDs, make sure it can handle DVD+R and DVD-R for best compatibility.
8. check the USB power availability. If you need an external powered hub, it's not so portable ('internal', removable drives may be driven by the USB, reducing that available for external devices)
9. be careful with extra-widescreens - not all programs are compatible (and wallpaper won't fit)
I hope this helps. I can't comment on good deals in the US; check out sites like Amazon, or other price comparison sites - preferably ones with customer reviews. Don't pay too much for something brand new - wait to see if there are any recalls/problems..