Please post the mailing address for ISC so that we can send ISC a check. Also please indicate small, medium and large amounts, as I have no idea what the effort is costing and how many contributors you have.
The http://www.isc.org/isc/ web page should tell you everything you need.
We run BIND, INN and soon DHCP.
Like the whole industry. And currently, as well as usually, our stuff is better than anything you can get commercially. I've seriously considered the Cygnus funding model as potentially superior to the X funding model we are using now. The current major release of BIND supports dynamic updates. The next major release of our DHCP server will use it. (In fairness, some vendors have this now, though interestingly, one I know of based their work on our stuff and plans to donate neither code nor money in return.)