Feat trees are listed on the D&Dsheets themselves in the feats section.
The Lion Tamer:http://www.dndsheets.net/view.php?id=4708
This build allows you an extreme amount of flexibility in combat. As a bard you can sing, trip, disarm, cast, whatever.
Note that each tree has specific requirements from ability scores. You already need a high charisma as a bard, and since the initial feats require a weapon finesse, a high dex is advised.
Note that CMB checks are attack rolls and weapon finesse does apply so long as you are using a weapon designed for that maneuver to accomplish the maneuver.http://www.d20pfsrd.com/extras/pathfinder-faq#TOC-Weapon-Finesse-9-25-09-
Scorpion Lash can be found in the Osirion, Land of Pharaohs book, page 29.
The Scorpion Whip, which allows you to penetrate armor can be found in the Adventurer's Armory at the bottom of page 4 and extending on to page 5. If you are proficient in whips, you are proficient in the scorpion whip.
Prehensile whip, which I like to call "Channeling Indiana Jones" also appears in the adventurer's armory on page 31.
As far as bard class features go, Versatile performance (Percussion) immediately gives access to handle animal and intimidate on level 2, both perfect flavor for the class. At 6th, Versatile Performance (Oratory) can give you Diplomacy and Sense Motive. If you're playing up the circus act, then why wouldn't a bard be the Master of Ceremonies!?
The Lion Taming Fighter:http://www.dndsheets.net/view.php?id=4740
The fighter obtains 4 more feats than the bard does, however one must go to the whip proficiency. The extra three feats open one new progression in the whirlwind trip attack into lunge combo. This set of feats turns you into a walking storm of tripping. Not to mention if you miss on anything and hit something next to it, you can use the scorpion lash immediate action attack to try again once per round.
Additionally, the higher BAB progression and extra feats really opens up power attack/cleave/great cleave.
You can also afford to take any of the suggested feat trees on the bard build and mix/match for versatility!
Please feel free to ask questions and I'll answer them as best I can. To address a few that are likely to come up:
Note that serpent lash only grants one extra attack per turn. So when I said you could use it with cleave it's only under the following circumstance: You can cleave trip, hit, then use the cleave feat's
extra attack to trip the next target. If THAT lands, then you can use the serpent lash immediate attack to get a third. Note that these must all be adjacent, and must all hit. It's feasibly within the rules as written to cleave starting in the center of a line, trip an opponent, then trip to the right with serpent lash, then say you cleave off the initial hit to the left. This is because of the immediate action from serpent lash interrupting but not ending your initial cleave action.
I believe it's also possible to trip one enemy, use serpent lash's immediate action to trip a second adjacent enemy, then take your cleave attack on said tripped foe to deal damage.
AS ALWAYS PLAYERS, REMEMBER: You GM can always rule zero anything I've suggested here away, even if its legal by raw. Play for fun, and don't be too hard on your GM!