Building a mana base for WGB Tokens in Standard
This is functionally a mono-color deck with some "color splash".

You don't need any color but white early on, so you can forgo playing Scars-block "fast duals" in favor of the appropriate "buddy duals", which are Isolated Chapel and Sunpetal Grove. If almost all your other lands are Plains, it's going to be pretty easy to get them to always come into play untapped.

However, if the green is mostly an afterthought, I would play Swamps before I run Woodland Cemetery. This is because you need more black than green, and it's nice to have lands that come into play untapped. Also, a couple of Swamps in your deck ensure that an opponent can't use Ghost Quarter to color-screw you out of casting Sorin.

Your mana base could easily support green splash, but I think Gavony Township might be too much of a "win more" card in this deck, since you've got so many other pumping effects going already. Township doesn't really start doing its thing until the late game, and my suspicion is that getting there in the first place means your opponent is likely using lots of removal to keep your creatures off the field. Initially, I was thinking that I'd prefer to have access to Moorland Haunt (to generate more Spirits) rather than Gavony Township (which is useless if I have no guys to pump up), and sideboarding in blue countermagic against Day of Judgment and Ratchet Bomb. However, with the full Dark Ascension set spoiled, I'm not thinking you're better off with green to support:


Ray of Relevation to answer Curse of Death's Hold and your opponent's anthems in the mirror.
Garruk Relentless as another token-maker and an Overrun effect.