Home Made Roaster

Hi, I am now planing to build a home roaster.

I will probably make something that looks like one of those miniature home coffee roasters.

What I have seen is most cocoa rosters seem to usePerforated stainless steel Sheet drams

What's the pros and cons of perforated vs solid drum for roasting Cocoa

http://www.home-barista.com/home-roasting/exploring-huky-500-coffee-roaster-part-i-t20245.html

Thanks.