Automate post to groups?

Hey all.
Im looking for some advise on this..

I have a few facebook accounts that are in a couple of 100 groups that are related to the niche I am targeting.
Im looking for a bot/automation method to do the following
Login account 1 > post to 20 groups > log out account 1 > login account 2 > post to 20 groups... you get the picture.

Ive tried iMacros, but somewhere a long the line it messes up trying to find the text box and the post button.

Ive had a look around here and ive found some "maybe" solution to my problem. ZennonPoster and uBot. Ive tried the trial on zennon but cant seem to get it to work like i want, would be nice if i could get it to scroll down to the bottom of my groups and click on the bottom one so that it rotates groups every time i log in, however it just clicks on the group that i recorded in.
uBot, does not seem to offer a trial and its a bit pricey just for what I want it to do.

Hope that makes sence on what i am looking for

Any suggestions welcomed

PPH script running on your server using graph api. run via CRON jobs. No need for logins, just change access tokens in script. Remember to have delay between posts from same account or you will get banned.

FacebookFriendAdder or CommisionKing can do that..
You can login multiple accounts at once, and do multiple task simultaneous and easy to use.
You can get a trial for FFA.