Confused on specs - Asus g73jh-a1 and g51jx-a1

Well your topic's title is about the specs of ASUS G73 and ASUS G51 but your question is something else.
Anyway i don't know the exact reason that why other sites(can you post which?) have it with 8GB but G73 supports up to 16GB RAM

sorry for the confusion.

asus itself says only 8gb is supported, also specs listed on new egg state 8.

g73
http://usa.asus.com/product.aspx?P_ID=8je5Ot4HBnKOdT81
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

g51
http://usa.asus.com/product.aspx?P_ID=bplbQOy6w8myYSq5

from xotic pc

g73
http://www.xoticpc.com/asus-g73jha1-order-p-2731.html?w...

g51
http://www.xoticpc.com/asus-g51jxa1-p-2724.html?wconfig...

You better ask XoticPC and tell them about this.
They have a great support