Title says it all. Stop trying to recruit tanks by looking for tanks. Start looking for healers. Talk to them and find out which tanks they have the best relationship with. The reality is that often when you recruit one person from a guild you'll get their whole following so rather than getting a half-ass tank then getting apps from all his friends...

Get an amazing healer!

It's way easier for you to recruit a healer because you can simply do pug heroics. Eventually...