Subwoofer Suggestion

Hi guys I need your suggestion regarding subwoofers. My system is composed of Focal Kanta 3, Kanta center, 706BK it would be used 50/50 for music and HT. My room size would be 13m by 4m by 3(Length,width,height). Would it be better to go for dual pb1000/sb1000 or single sb3000 or single pb2000 or single PSA S1500?
king baracyda I'm located in Philippines, everything here is so expensive compared to US.

El Pipe-O is a DIY sub. Quite a large variety of woofers can be used as drivers. I’m sure you could find a suitable pair locally. 
Well I'm not really looking for a diy sub, but if all else fails I'll give it a try thank you.
I bought 2 SVS sb2000 subs on sale for $650 each (price reduced when they brought out the sb2000 pro model).  They compliment my Martin Logan 60XT towers.  I set the crossover at 80HZ and let the subs handle frequencies below that.  Room placement is not optimized and I seldom play music real loud.   I’m not sure I have them dialed in correctly — read somewhere that mains show be set at 20 HZ and let the subs handle below that (?).  Don’t know if that advice works or not.