Ok...I have a set-up but not cheap...but works, works well..and is very rugged...
First you need this...
Motion Computer C5 they make other models...but this is dual core and you can bump the ram up to 4gigs....it also has the bright-sun display...you can see in sunlight....battery life is about 4 to 5 hours...once booted and on long life...if your carefull you can get almost 9 hours...(I always try to edit something while on the go)...
Second...you can use eyefi slow...so I picked this up...
From here on ebay...
Wireless USB for Tethered Photography. Canon/Nikon/Sony/Mamiya w/Digital Back
It's a little bulky but works...another good computer to tether too...is the Sony UMPC UX380 series or better....
the Motion C5 is a better pick...the sony is a lighter answer....
Hope this helps out...works great...on the Sony and Mamiya take a little other adapters...then works great....