I could finally complete this subwoofer last weekend and attached are some images. I am currently driving this sub using a DNM subwoofer amplifier which is around 60 watts class AB type amplifier. I have crossed them at 150Hz and using the default level. They integrate quite well with my main OB FR driver and the setup took less than 5 minutes to achieve.
I have placed them slightly behind my right speaker and there is around 3.5 feet distance from the front wall. So there is quite a good breathing space for the sub. i initially tried placing them 90 deg w.r.t the front speakers but the bass was suckout. I later tried 0 deg with front speakers the bass improved but not to my satisfaction. I later tried inbetween at around 45 deg and at this position the sub began to sing. Now they sound very tight and very very well integrated with the fronts. The integration is so tight, i hardly feel that the sub is playing. All the bass seem to flow from the front main speaker and the sub completely disappears from the scene.
Now after listening to this sub for over 3 days, i can confidently say that H-frame OB sub is the way to go for small to medium size rooms.