The article is empty link bait, using 'Mumford and Sons' to get views.
While I am also not a fan of the band, this 'article' doesn't suddenly make them Lars. The 'warning' seems generic speak slapped on things. A Google search shows Velvet Underground records from the 80's with this warning.
Also, a lot of people think The Avett Brothers are considered a 'poor version' of folk music(easy listening, pop) in the same bucket as Mumford & Sons. Regardless of versions and quality, both are nice to listen to on summer days with friends(who often don't care much about music), regardless of who's imitating who.
You'll need an amp. http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-...
To run from the headphone port you'd just use a simple male 3.5mm male to RCA(red/white) male.
I imagine the headphone port quality is terrible and the post mentions it. Apparently this is a cheap USB compatible option http://www.meritline.com/usb-sound-adapter-channel-volume-co...
This entire setup should run you well under $100 and sound great.