Something like this is a low height htpc case
KustomPCs.co.uk - Antec Micro Fusion 350 HTPC Case
All the decent cpu coolers require a backplate on the mobo so taking it out otherwise you run the risk of it falling out and smashing everything on the way down and it has happened to some idiots that don't bother with backplates.
The golden orb 2 is an ok cooler its better then stock but its not particularly good value for money or performance due to it being designed for the small form factor market.