Vistaprint seems cheaper than Moo, but by the time you add in the cost for printing on both sides, being able to add your own artwork, having good fonts, and using the really nice heavy matte coated paper, Moo comes out the winner. There is just no comparison on the paper quality. Moo is ultra luxurious.
I am a huge Moo fan (many orders under the belt) but recently used Vistaprint for some cheap cards for a show. The quality is just not there. They printed them off center and even the upgraded paper feels cheap.
I use Mini-Moo cards as cards that I include with orders. They're small (therefore cheaper) and unusual looking enough that they're likely to be remembered. But the biggest advantage to Moo is that you can upload a different picture for each card. So if you have lots of photos of your artwork, you can get a whole array of cards with those images on them. That's particularly nice if you have multiple lines of work that you will advertise in different places.
I agree about not making the card too busy. All you really need is your name, tagline, and your web address. Plus a picture of the kind of work you do. Address, phone number, etc are not needed if they're on your website and if you don't expect people to contact you that way. Also include a Facebook icon if you have an active FB page (and make sure you have an obvious follow button on your website).
If you use your website as home base, you can then redirect them where you want them to go from there (such as Etsy, FB, or subscribe). The business card just needs to get them to the website (which, of course, you should have all decked out with gorgeous photos of your work).