I have used several, netbooks, notebooks and laptops and really have no preference beyond usual system specs (processor, RAM etc). I use BT4 on VMWARE workstation and for wireless I use Alfa 500mw usb adapter so never have any issues with drivers for the adapter. I've even found no problems going from XP to Windows 7 (never took to Vista at all).
My life is this forum
I've been using an Asus 1005ha in conjunction with a desktop.
The netbook worked fine with a standard install. It needed nothing except for a new wired ethernet driver... the wireless one seems to work fine and injection does work. It's great for taking along to locations and doing de-auths to catch the wpa handshakes... for the real grunt-work I take the files back and run them through my desktop.
I'd definetly recommend that model Asus. From experience I can say it works wonderfully with BT4 as long as it isn't used for tasks that tax its computational power.... you'll definetly need a desktop for most things.
It really is great though for the size / battery life / ease-of-use.