Hello Aman,
given the difference in speeds between the two links I would consider a setup where ISP2 link is primary and ISP1 link is secondary and used only if primary link fails.
You have not provided any information about the topology, if the two eBGP sessions are terminated in two different border routers or only in one router.
An attempt to perform load sharing over the two links can be done using DMZ link bandwidth feature. Because both links are from the same ISP you don't need to play with hidden commands to implement load sharing.
Read the following document about DMZ link bandwidth
configuration example:
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t2/feature/guide/ftbgplb.html#wp1047641
feature description:
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t2/feature/guide/ftbgplb.html
Hope to help
Giuseppe
