I can't tell you much about the Guhong v2 since mine was messed up (explained below). I've heard a lot of good things about it though, so I think you should give it a try.
The MF8 Legend stickers are actually considerably smaller than standard stickers. If you can, get half-brights from Cubesmith (
http://cubesmith.com/3x3x3.htm) but if not, just stick with the standard vinyl stickers (
http://www.icubemart.com/apps/webstore/products/show/1885151).
As for lubing, lubricants that work well on storeboughts don't necessarily work well on speed cubes, as the plastic in storeboughts is different. For example, CRC worked okay on my storebought because it pretty much rubbed away at the plastic and made it softer. But when I used it on my DaYan cubes (including my Guhong v2), it stained it and actually slowed it down a bit after a while. The only good thing I got out of that was that the cube was smoother afterwards. I ended up buying a new cube and lubing it with Traxxas 50k diff oil, which I highly recommend. You can typically get this from a local RC store. For best results, follow this tutorial when lubing:
http://www.youtube.com/watch?v=s4paID_54lQ.