Hormah.
For other sites specifically, I've always liked the idea behind
Banks of the Nile / Pharaoh's Court since it changes brigades and
could lock out your opponent if they don't have both, but they are common brigades.
Teal sites are generally good for lock-out from what I've seen due to the lack of priests that actually get used for rescues (plus they have negative effects if non-priests have access to a soul there).
For souls, use the
Hand Discard and
Deck Discard. These go well with Hormah especially, but you can use them multiple times by also running
Beggar (can shuffle in the hand discarder) and
Evicter.
Wanderer is very useful, especially to grab something good they have. It's not especially powerful, but
Color Guard can be useful to counter your opponent's territory destruction on offense if you get lucky on the site brigade compared to their offense, but it is very limited. Often, running a
Site Doubler is good for when you don't have enough sites, or when you want to load up one of them because your opponent has no access to it specifically.
While it may not seem related to sites,
First Round is great because it can sometimes buy you that extra turn you need to draw a site for it. For the same reason, it
may be beneficial to also run either a
Two-Liner or
Three-Liner, because you can afford to give them one on it and stall a turn to draw sites (it also works fantastic with Hormah, since the rescue count resets once it hits deck again).
Otherwise, using the standard protected souls (
NT Only,
Female Only, and to a MUCH lesser extent anymore,
*/4) is recommended. They can often sit outside of sites while being protected, until your opponent finds the one woman in their deck, the one NT angel they are using, or a way to negate souls for example. This lets you maximize the use of your sites, by using them for your unprotected souls that may have better abilities in a site.
CBP is a must in pretty much any deck that uses actual defense with enhancements, but if you're relying on site lock alone, wouldn't worry about it.
Hope all that helps