So essentially what you're saying is would we rather have more talent or reach a wider audience? I'd have to go with the obscure/more talent option. If you're good, then you will naturally start reaching bigger audiences, and you'll get more work. Plus, normally people don't look up artists unless they're interested in art anyway, so doing a cover can nothing to most people. You'd have better chances of reaching art directors by publishing work in Spectrum or Expose, which only the best get into.