I like to get generic misspells that google/overture pay big gor these keywords, I also find misspells sometimes take a month or two for SE to pick up but can get placed pretty high, I use google to check names potential quantity of misspells when overture automatically shows the correct spelling. I type "correct spelling" in google results to get my baseline total then I "check misppell" and get a idea of mispell percentage to correct spelling
good luck