I've got the ASUS Eee PC 1005HA (Atom 1.6GHz NetBook)

It comes with an Atheros Chipset wireless card and everything works great out of the box

As long as you won't need to do any password cracking you should be fine with it.

Don't get me wrong, but it's a great netbook, and works perfectly but it's not designed to high performance so the password cracking can be a little slow but still achievable.

There are two different models of the 1005HA, one with at 1.6GHz and one at 1.8GHz which also includes bluetooth.

I got the 1.6 as I didn't need/want bluetooth, and yes they both have 3 USB ports.

alucian   what would i need to be stealthy   you say?     not a netbook  ?   

I would not recommend a netbook because it is too small and not powerful enough. If you want portability buy a 12 - 14" and if you want to do more than wireless cracking buy one 15 - 17" with a resolution of minimum 1600x900.
I recommend a good resolution, because you'll want to have more windows open in the same time (example: 2 shells and a browser, or a browser and burp...).

Also, don't put too much in a laptop unless you are rich.

For example, I just bought an used laptop, Dell Precision, core 2 duo, 4GB RAM, 17", SSD and I will use it for normal browsing and I have 2 OS windows and Backtrack.
Next week I will buy a server, dual CPU XEON, 6GB RAM, 2HDD and I will put my VMs, I will use it also as an web server, as a test machine...

The total price - 650$

If you buy a good laptop 17", it will cost you more than 1000$, without any return on investment. Worst, in one year it's value will be 700$ max.

I am giving you these advices because I saw that you are on a budget. Otherwise... buy the most expensive MAC, put a Linux as a dual boot and .... you'll do the same work as I do

PS I am wondering if in few years I will have the same judgement 

At least Penetration tester should have a good performance Computer/Laptop. If you are going to buy low performance laptop then in future you will be having some problem(It happened for me)...

Some Problem if get a low performance laptop:

1. You need low budget for buying a Low performance laptop. So Screen may be lower than 14" and after some month you may loss your eye power ''' heh.
2. What if you are going to crack a hash or a list of hash? Your laptop will be too slow and you will be unable to do others work at a time.
3. multiple tasking will be boring.

In my opinion if you budget problem then wait for some time then go for "good".     

I'd give it the 8 GB soon, in the event you want to load up VM's, but that should get you started, if that's what your budget affords.