So you are looking outside of your village for an adapter. Why not look the same way for an ATmega8L PDIP instead?
Many of us know how to create an adapter. If you have enough money you might convince me to make one. It costs hundreds to make a new PCB design, prototype, build, verify, and test. HOWEVER when you pay me for an adapter I reserve the right to simply take a 28-pin PDIP ATmega8L out of my kit and send the PDIP part to you instead. (I will keep the rest of the money).
You will have an ATmega8L that fits in a PDIP socket and I will be rich.