If you're looking for a higher density foam look up foam tiles for garage gyms or kids play areas, anti-fatigue mats are a bit heavier, also stolen foam from memory foam pillows.
Get a cheap rifle and whatever glass you can afford(I hunt with a 200$ leupold). jb weld bed the action g2g
if you can swing it get a stainless rifle drives up the cost but I think its worth it. if not rattle can the rifle, cheap rifles bluing dont seem to last and rust