Right now for all of my business trips im rocking a sony vaio ultrabook 13.3 , i love it its bigger then a net book and has enough ram and space for me to do whatever i need.
Dell or HP is used a lot in business. but I'd always recommend Toshiba. I've had dell and hp crash before. but never has a Toshiba crashed.
You did not say what business. Have you considered not even using a lap top and going with an Ipad or android tablet. You could run a local wi-fi hot spot from your cell phone.
I have a Lenovo, but next time I will probably go with Dell because of the next-business-day warranty.