How do I configure NAT rules when using ASA IP-SLA when leveraging post-ASA-8.3 NAT syntax?

The way that we deal with this is to create an separate object group for interface that we want to have redundant connectivity to, it is a little messy but it should work for what you need.

So you would have a FIOS object

object network FIOS_NYHQ_GUESTWIRELESS_10.110.6.0_24
    nat (NYHQ-GUESTWIRELESS,NYHQ-OUTSIDE_FIOS) dynamic interface

and a Cogent object

object network COGENT_NYHQ_GUESTWIRELESS_10.110.6.0_24
    nat (NYHQ-GUESTWIRELESS,NYHQ-OUTSIDE_COGENT) dynamic interface

And you should be all set.

It is a pain if you have multiple servers and multiple upstreams, but it works for us. I am sure there is a more streamlined solution and am interested in what others are doing to solve this issue.