UPDATE:
Purchased Win 7 PRO 64-Bit successfully upgraded to Win 10. Note: Initially sent the Technet/MSDN license key, resend OEM key after some enquiry. Make sure to check after the installation as Technet/MSDN is considered as Enterprise License which are not entitle for free Win 10 upgrade.
User is happy with Win 10
By the way, purchased Samsung 850 EVO 256GB from Lazada at $129. Fast delivery.
Last note, thanks for all the input and tips.
How to tell if it is a MSDN/TechNet key, retail key or OEM key? Possible to tell from the product key code itself?