Several companies make shooting sticks that are light and meant to carried while still hunting/stalking. I know of one that attaches to a gun sling, and they deploy quickly. I don't know if they are noisy. For all my stillhunting, I don't bother with shooting sticks. My shots are always under 100 yds and I can usually lean on a tree for a longer shot. If you will be spending much time in one spot watching a field shooting sticks may be a good idea.

Be sure to check how the scoped marlin fits your frame. You should shoulder the gun, close your eyes, and put yourself into a comfortable shooting position. Then open your eyes and see where you are in relation to the scope. You may need to move it forward or backward (more likely if the gun was set up for someone larger than you) in the mounts to get the proper eye relief. You'll know it's right when you see a full sight picture inside the scope. You can test this by moving your eye closer to the scope and then further away. There will be a short range somewhere in that motion where you see a full picture.