I was on the waiting list for GL5516's forever. Now I see they're not in the offering of components on PPCB. I wanted to build another General Tso, but have been frustrated by the difficulty in sourcing them (or equivalent) elsewhere as I'm not a REAL electronics guy able to fully evaluate the specs. There are Ebay or Amazon sources that leave me leery as to quality and you gotta buy in "bulk". Any suggestions?