Nice thread!
Personally, I’m a fan of office clothing - for starters - it’s cheap and readily available from charity shops. My Zombie ‘suit’ has kept me happy 3 or 4 times now and I love it.
My main decision is deciding what to stick in me! (ahem)
Last year, I stuck a regular kitchen knife in my chest. Did the trick too, it looked great!
I bent the end of a knife in a vice (cheapo softish metal knife, that is), then bolted the right angle to the top of a baked bean tin. I then covered the sharp edges and gaffa-taped the whole thing to my chest. Put putty around the bolts and squirted the blood on - it was awesome! You could grab the knife and wiggle it - it wouldn’t budge and my chest would eerily move around with it. Top tip!