>the one big thing that this one has going for it is its noiselessness due to using its case as a heat sink
I am going to disagree with that: IMHO the one big thing being fanless has going for it is lack of need for maintenance. Specifically, without a fan, the case can be designed so that much less dust gets into the case, and dust and moving parts are the main causes of need for maintenance.
The cost-effective way to lower noise is to use better fans (longer blades, better bearings, lower-RPM motors) or to use solid-state drives.
The company that makes the computers featured in the OP also makes a fanless computer powered by an Ivy Bridge Core i7: http://www.fit-pc.com/web/purchase/order-direct-intense-pc/. But they want $836 for the barebones (no RAM, no HDD) version!
One reason the price is so high is that they are forced to use an ultra-low-power (17-W-TDP) processor. If you add just one fan to your design, you can easily accommodate a 65-W-TDP processor, and in fact Intel does not even sell a retail processor (i.e., a processor marketed to people who build their own boxes) with less than 65 W TDP. To be precise, they didn't sell any such retail processors before Ivy Bridge started coming out -- I have not checked since then.
ADDED. I am talking here about systems with some oomph: if an ARM or an embedded-class processor will do the trick, then obviously being noiseless (and compact and low in power consumption and low maintenence) is easy.