Arjz wrote 

my concern is the internet speedtest result from client side did not reach 50mbps since my AP from home has 50mbps on it.

 

are there anyone that you can suggest?

You can try to set 802.11n-only mode, 20 MHz channel bandwidth, turn MAXtream off and set the Distance setting accordingly. But reaching 50 Mbps in 2.4 GHz band can be difficult, it strongly depends on how many foreign APs are around.

for the tower infrastructure there is a one 3 storey house block my pole(next to mine)  do you think it would still matter? or do I need to increase the height of my main pole so I can get a better or a high speed internet from my client ap?

Of course it matters for directional links. Make sure you have fresnel zone clearance, this will determine the required height of the CPE on a pole.