Sean,

Like OME said the MakerFarm plywood frame is not really a good platform for bed expansion. I have a 8" i3 and I am reprapping a http://reprap.org/wiki/Wilson TS that uses 2020 extrusion and can make any size bed you want. I have printed all the parts on my i3 and can salvage all the electronics from my i3 to get it running. This photo is for the 200x200 bed. I have the 2020 to make it a 300x200 once I find a 300x200 heatbed instock somewhere.

RepRapWilsonTS.jpg

But it sounds like you are just getting your i3v up and running. I would suggest you get a few cube prints under your belt then start tuning it. A fun object is the Make: Robot used in their printer tests http://www.thingiverse.com/thing:40212 See how clean you can print the little guy. Then once you are happy with that go for the Make: Tourture Test https://www.thingiverse.com/thing:33902

aBrainDump