Welcome aboard! Glad to have you with us. How is the PDI chamber working out for you? Or have you yet to shoot her since the sears need replaced?
Check out airsoft atlanta for a variety of sears, trigger boxes, etc. Also, airsoft extreme has a few z-trigs in stock for somewhat cheap, as well as a few pistons and such.
And feel free to roam the boards. Some of the older topics back in the day have some great information as well as some of the new ones. Let us know if you need any help of the sorts!