Go for standard metal, maybe with venting holes.
Perspex/Acrylic looks very catchy at first sight, but gets old really fast (like a transparent acrylic PC case vs a classy Lian Li aluminum case if you catch my drift).
Venting holes are included in both versions of tops..and i know what u mean..i once had a full aluminium lian li case..timeless beauty! Thanks for sharing ur opinion..never thought about that!!