Actually, I do not use any "re-steem bots". In many cases it is just loss of money. If you want just bid-bots, I recommend https://www.steembottracker.com, where you can find the current rounds of giving out upvotes of every bot (probably not every but most of them | calculate there everything, you presumably do not want to be in loss). Some of the bots are actually real people who read some of the posts, the bid-bot upvoted for them. I once got resteemed because of that. I also use @minnowbooster and @smartmarket. Both of them "guarantee" profit from your bid and they also use users as a voters (you can give your Active Key to them - to the Steemconnect - and they will give you your percentage) but currently their services are "unavailable", because users buys their upvotes so much that there are not of them left. But right now, you can buy 3.2$ upvote from smartmarket because there is some free Voting Power right now.