Hi there: as I gathered you are the current maintainer of Sangband.
I've been meddling with monster.txt, trying to make Sangband fauna more interesting - adding 60+ new monsters and making "Z"s less common (from 2 to 3) as it seemed for me that "Z"s should offer more space in deeper levels for other monsters.
I also have some more "Interesting rooms" in vault.txt plus few new objects. I did all this with respect for Angband classics and good-taste in mind, focusing also on balanc - so if you are interested, I can send the txt files.
Lets make the Sangband a bit more colorful.. why not?