My experience is that no rain jacket or pants will keep you from becoming soaked in sweat. Even the so-called "waterproof breathable" fabrics are not ventilated well enough to prevent sweat buildup during even moderate exertion. The fact is that you produce more seat than can be transported away through these fabrics. On a rainy day, you should pack you clothes in a waterproof bag and change when you get to work.

Water resistant clothes generally do not stop rain for very long. Since you will be wet anyway, the issue is whether you will get cold with the rain seeping through the fabric.