There has been somewhat of an increase in male Lee's on these sites for tickling in the last several years, though. And you know, in my opinion, for the most part, men who are lers seem to be more open to switching than women who are lees. With men who have only been or mostly been lers, their main concerns seem to be that they either wouldn't be ticklish at all, or that they'd be TOO ticklish and couldn't deal with getting a taste of their own medicine. With women who are lees, for the most part, their concerns about switching seem more complicated. They seem to identify strongly with the submissive role, feel uncomfortable taking a dominant role, and most importantly, feel uncomfortable with seeing their man take a submissive role - I've often heard when this is discussed that it would be a turn off and that they feel like they wouldn't see him the same way they do anymore if he was ever submissive.
This isn't a problem for you because you're clearly curious about switching and liking the idea of being his ler at some point. While some men will always be only lers - let me tell you, I think there's a lot more kink/sexual curiosity among dominant men about having the tables turned. Over the years I've talked to a lot of people into tickling, and among men who are mostly ler, when they've found out that I'm a switch who can tend towards being a ler, many of these "mostly ler" guys wanted to ask me a ton of questions about what it felt like to dominate a guy with tickling. They were curious and often, if they had a partner, nervous to ask her for this because she had not expressed interest in anything but submission.
The first step is to talk to him about what you want. He may not be comfortable with it, but you never know, he may be more open to it than you think he would be too, and in the best case scenario he may even secretly desire this.