Safety is an issue for me, I see too many taking unbelievable risk for the sake of a couple fish. So butting in with my 2 cts.
There are a few kayakers I know who wear gortex waders, stocking foot with neo booties, with a belt and a dry top and PFD over them and they have had no problems. They have tested this arrangement by practising dumping and re-entering. If you wear waders you need to absolutely keep water out of them or you'll a tough time getting back in the boat. Personally, I don't/won't wear waders in the yak. Suggest you look into a wetsuit. Fleece under a dry top is great. Best test is put the gear on and jump in the water. Practise dumping and re-entering in deep water with yr paddle float wearing what you choose. And then practise doing it in rough water. (practise with a buddy around). I don't know what you paddle but I doubt that a PFD for your yak will do much, most will roll pretty easily when they're full of water as you will see when you try to get back in. Check your float bags regularly and make sure thay are secured in the boat, not much help if they float out.