Layers are the way to go. You can use the same rain jacket year round as your shell.
For the jacket get a good (NOT just DWR) rain jacket (I use a Helly Hansen 2.5 jacket). Helly Hansen, Outdoor Research, Patagonia, etc are all good options. Sailing companies typically make good stuff, pay attention to the millimeter waterproof rating. The 2.5 layer fabric is a nice blend of breathability, packability, and waterproofness imo since I don't want to be sweating inside the jacket. If you happen to work as a first responder, outdoor professional, military, etc most of these high end outdoor gear companies have a "pro" program you can register for and receive 50% off your purchases.
Underneath that, as it gets colder layer whatever you already own for an insulation layer (polyfill puffer, wool sweater, stanfields, etc), I would avoid down fill in this case just in case you do ever soak through your jacket since it will lose its insulation capacity when wet.
For shoes I don't really have a good recommendation since I just use waterproof socks and wear whatever shoes I feel like.