Hi Jonathon - just in case you haven't found what you're looking for:
cheers - Wolf
If you are still looking have you got a local army surplus store. They sometimes have scrim and camo nets at reasonable prices.
From personal experience I can definitely recommend Wildlife Watching Supplies' bag hides. They cover your whole body, with space for a camera and tripod, and not only disguise your shape but help stop your scent spreading so much. The heavier grade bag hide is also waterproof, which is great in case of showers. Go to a place where you expect there to be wildlife e.g .from seeing tracks, at the right time of day (probably around dawn), and so long as you stay still you can see lots. I have had deer - which have great vision and sense of smell - coming very close to me without even realising I'm there. Top tip though: get a padded mat or cushion to sit on, as that will help stop you fidgetting!
I use Realtree or Jack Pyke camo veils/balacalvas. They probably do help, but it is more for personal comfort. If you think you are hidden, then they will work:)
I use camo gear to hide from people. I am not sure if it works with animals and birds? Some possess almost infra red vision so camo gear doesn't work as intended. But, a Gillie suit will break up your shape and help get closer to wildlife. Just the other day I spotted a young Roe deer and wanted a closer look. I was wearing a blue polo shirt(workwear) and blue shorts. I stooped down and watched as it moved closer. It looked straight at me and ignored me completely. It was less than 8 feet away and perfectly at ease. So, is came gear necessary? Maybe, maybe not. But Jack Pyke gear is designed for UK, Realtree is USA. Hope that helps?