Around 4k poly's should be fine for vrchat, tho you could get em down to 2k and still have em look as good. Here's the topology from a model Made by "Jaws". Youd only have to worry on the area were the Shaft and balls connect and the tip/urethra wich is basicly the same topology as per say a nipple.

Working on It, on my free time

First 2 are amazing.