50 ip is ok to go with that 1K non pvas. What matters is to have non-sequential proxies and to not overuse the proxies. Ie.: If you want to post 24/7 you most likely will get them flagged at facebook. Dont use the same proxies for friend adding, buy another batch of accounts and IPs for that. If you want to add friends then watch it how fast you are logging into the accounts after each other.