My business wants to do a small scale Facebook Advertising campaign to US consumers to see what kinda of response we get - should we manage ourselves or pay someone to manage for us? If we do it with a third party, any platform you guys recommend?
Just do it!
No, seriously, I'd not recommend to talk to someone, because it basically is more a thing of getting to know the interface and the quirks of doing x and y.
I'd neither advise someone to start using a 3rd party if you do have someone who can invest a bit time to learn the platform. However, if serious scaling is a close requirement, then you're forced to either get an in-house team or outsource it.
I usually reach <.5$ CPA and I also usually have best experiences with testing myriad of AD sets. Keep in your mind, always testing:
copy: tone, audience keywords, actionable keywords etc.
image: emotional triggers, quality, visual objects etc.
target audience: try to refine your scope to your buying persona, not your marketing persona
Here are some resources to begin with and set you up on a good track.
This is comprehensive enough to introduce you to most mechanics:
https://adespresso.com/academy/guides/facebook-ads-optimization/
This is a short list of what to optimize for beginners:
http://www.socialmediaexaminer.com/optimize-your-facebook-ads/
If you do not yet know what you want to achieve with the ADs (brand-awareness, retargeting, CTR, other actions or conversion types), this post is listing most types and its use:
http://www.jonloomer.com/2015/05/05/facebook-ads-bidding/