The Marvell 88E8056 works with Apple's drivers - AppleYukon2.kext in the Plugins folder of IONetworkingFamily.kext - but you need to make a small modification to the info.plist inside it.

Once you have info.plist open, right click the entry for the 88E8053, click copy, then right click 'IOKitPersonalities' above and paste. Rename your new entry to Yukon-88E8056.

Then, all you need to do is change the value of IOPCIPrimaryMatch inside of it to 0x436411ab.

For the neatness freaks out there, you can change the model string in your new entry to be 88E8056 instead of -53.
You can also drag it down so that it appears in order after the 88E8055-B0, you have to click to the left of the little 'expand' arrow and drag, if you try anywhere else you will make a mess..