GoreTex is what the best jackets and trousers are made of. It is waterproof and generally very good at keeping water out, although it is also breathable. Cheaper, none GoreTex waterproof outfits tend to have a plastic type lining inside them and they tend to retain the heat and sweat and you end up getting wet from condensation rather than rain. I just got my first GoreTex suit (Hein Gericke Master IV) after previously using a Frank Thomas Aqua Pore suit and it is a massive massive difference and well worth the money.
You should be fine taking your boots. You may find that the leg length on the trousers with the right waist size, end up being slightly too long or too short for your boot top level so you really need to try them out together.