Connecting datacenters between US West Coast and India - Need advice

Can some experts here chip in with some expert guidance, please?

I am trying to sign up with a Colo provider in West Coast (Am inclined to HE Fremont, or Switch Tahoe Reno) to run an OpenStack private cloud.

We have an offshore delivery center in Chennai, India, where we intend to set up another OpenStack instance. These two Openstack instances will be connected to each other for redundancy / disaster recovery.

Questions for which I would like guidance:
1. We are planning to get an ASN in Asia. Will the Asia ASN suffice to assign IPs to the OpenStack region in US West Coast or do I need a separate ASN for each?
2. I assume that we will connect the two locations over VPN. But, how do I determine which ISP in USA and which ISP in India can set up a VPN connection, to minimize latency? I assume we need to identify ISPs on either end, who have some kind of peering relationship. Not sure how to go about it, since the service providers are different. In India, we have quotes for Internet connectivity from Airtel, Vodafone, Spectranet. In the US, I assume it will be AT&T or someone like that. Can someone advise on this?