You should at least mentioned what projects you want to be shilled. Why don't you just paid them in BTC though? No need to say "coin of your choice" because I'm sure they will choose Bitcoin all over other coins out there included your native token. Usually they're social media influencers, Twitter, Facebook and Youtube will be the best outlet to spread the word.
Maybe there are some who do like some BCASH and XRP.
He wont tend to disclose on what coin or project he wanted to be shilled.
0.2BTC for few minutes of podcast and reviews.
People do really love to waste up some BTC.