Hi Venkat,
The Support Pack stacks SPS08, 09, 10... are all cumulative
With HANA evolving you mostly have new topics added in the latest versions
As indicated in the links I provided before Training.sap.com confirms that SPS10 course material can be used to prepare for C_HANAIMP151 but it does not say it is mandatory to use SPS10 course material
When you purchase the voucher you will only see the certification code C_HANAIMP151. It will not have options for SPS09 and SPS10 so you should not have any confusion during the purchase
Hope this helps
Sunil