I would need to do a more in depth post on what I use but mostly I use tech shirts and lightweight quick dry camping pants. The kind with a removable legs that convert to shorts.
I use the simms guide guard socks and wading boots mostly. Sometimes the socks worn knee high and sometimes folded over. I use the simms freestone or freesalt boots. On a trip to Colorado I bought a cheap pair of synthetic hiking boots a size up for 50 bucks and they worked great and are still in rotation. I put grip studs in all my wading boots it makes a huge difference in safety and traction.
Regulating heat and layering is important.
Another product that is a staple is the under armour cold gear compression shirts. They are like a wetsuit in a lot of ways and can keep you warm even when wet. You will need wind break so a packable rain jacket is also a must. Look for the ones that pack down to a soda can size. Most rain jackets are really poor in rain, but serve excellent as trapping heat and preventing evaporative heat loss in wind.
I dont use knee pads a ton but when I do I use these sailing ones