I'm also in Ireland and I've also found that a majority of jobs are as you say -- Java, .NET and frontend roles. I work primarily with PHP (three years industry experience) but there are only a fraction of positions available for it and so I've been tempted to step in to contracting, especially as the idea of working more independently really appeals to me.
I have the same assumption in that I've always seen it as a pipe-dream at the moment and that I'll need another five years plus and additional languages under my belt before I'm worthy of even considering contracting, so it's refreshing to hear that this is not the case! I'd be interested in hearing more about your experience in making that step to contracting, and how you felt yourself 'ready' for it.