Walk-thru baby gates

My hubby and I are in the process of purchasing a 3 level townhouse, so that means 2 sets of stairs with an active 2 1/2 year old and a 6 month old who will be on the move shortly.  :o)

I need some brand names and suggestions on good walk-thru baby gates.  Even if they need to be attached to the wall, that's OK.  I want one at the top and bottom of both sets of stairs so I will be buying 4 of them. 

Thanks!

http://www.amazon.com/gp/product/B0012EUL0M

I love this gate...It has been sturdy- we tend to rip them off walls or abuse them.  It washs up easy...I found it at BRU but I am sure there are other places to get it. (I am not sure they still carry it) It curves for the steps so you have room to stand.  A+++

We have this one and LOVE it!

http://www.toysrus.com/product/index.jsp?productId=2265804

It goes across the length of our living room/dining room area so she can't escape and play in the bathroom, dogs bowls, kitchen, garage, etc.  :-)