laclean The site http://www.ledbenchmark.com offers pwm data for many led lights and full comparison site including price.
laclean BTW one thing this is missing is flicker frequency. But assuming you don't have headaches from incandescent lights(which also have some very subtle 50hz flicker) ,maybe selecting a led with better flicker parameters than an incandescent would suffice.
JTL And I don't think anyone has problems with standard incandescent assuming the bulb and the underlying electrical system is working properly as the off period is very short compared to other forms of lighting as it has to cool down.
JTL Frequency is there, take this one for example. Frequency doesn't mean the classic PWM, as the graph doesn't look like it. http://www.ledbenchmark.com/images/led_store/286/flicker.png
KM It's very hard to find the 1% flicker bulbs they tested. Amazon, eBay, nothing. Not even the ALDI bulb (MD 13890) shows up in a Google search. Most of their shop links don't work.