I need a new handbag....not again....sigh....

I am gutted. My purple bag is showing signs of tearing and I have only just bought it! I am so sad about this! I am going to have to replace the bag before I have my holidays in September because I can't be without a bag at fashion week. Mind you, it's totally my fault for carrying stupid heavy books in it. I am currently reading Shantaram which has 936 pages - this, and all my usual crap mean that I am carrying the weight of a small child in my bag!!!!
So here are a few contendors

TOPSHOP - £60. I quite like this but I would concerned about the suede in rain - about how it would hold up and would the color run which dyed suede is apt to do....
You can view it here

CAMBRIDGE SATCHEL COMPANY - £105 - This is the big one. I have wanted one of these satchels for ages now and I am gutted that I have never come close to owning one. This took over from the Alexa as the bag I would happily kill someone for. I have tried saving for one but everytime i get close - it never happens!!!! Mind you, I was given a tip off by someone that if you go for one with a minor flaw on it on the website then you can get it for a lot cheaper then you would normally.
You can view them here

ZARA - €70. This one I quite like. It ticks all the boxes. Reasonable price, leather, black, zipped, waterproof and with a handle long enough for me to feck it around the place....hmm...a real contender....
You can view it here

So I am really not sure. I mean, I am looking for the following in a bag :

1 - waterproof - this is essential in a country that rains as much as Ireland. Like its important that my Ipod remains dry!!!
2 - Color stays put!!! Again essential in a country that rains
3 -  It can take a large amount of weight because I read heavy books. A lot.
4 - Possibly could carry a laptop.....although I am flexible on this one!
5 - Must have either a strap that goes across the body or a sizable shoulder strap so its not just under my armpit because that is bloody irritating!!!!
6 - Must not cost a small fortune!!!!!
 7 - Must not need to be dry cleaned because i will forget....hence why my Vivienne Westwood is still in the closet....sigh...

Jesus, I'm not asking for much am I!??!?!? That's the holy grail of handbags!