The more the better for tx propagation and block validation. I think 5000 is good enough, if it grows with the number of txs, not reduces.
Thanks for your time, but i am trying to determine how much it would be helpful if i setup couple nodes.
I want to feel that i am doing impact, would something will change to the better if i setup at least 1-100 nodes?
It would help - everybody should run at least one full node on a good connection to help with the network breadth. one node with good bandwidth and full blockchain is much better than 100 nodes on crappy network lagging behind, these do more harm than good.