Mini ac/dc smps source?

I frequently use very small 110-240vac to regulated-5vdc smps's that I gut out of very small wall-warts from thrift stores. They work well in compact projects that need both 110vac and 5vdc in the same box. I'm currently doing a project that requires that I make three identical units. Finding three identical smps wall-warts at Goodwill, to gut, is not likely. My DC current requirements are small, probably less than 50mA. Anybody know a cheap commercial source for these PCB supplies (not the wall-warts)? Or a cheap kit? Google'ing has not gotten me anything useful.

Also, I need isolation, so the series-capacitor/rectifer/zener type

Thanks in advance.

Ken