I've got the Cabela's MT050 rain gear, and both pants and jacket pack down into about the size you're looking for. More expensive than the space rain gear, but mine have lasted 4 hunting seasons (turkey and deer) and no rips, no tears.
I AGREE
I have used mine for many Colorado elk hunts and lots of hunting in thick stuff back east. Simply the best I have found. I have (2) pairs of pants and theh jacket. It is all take anymore......even if it is not raining;)