1. I'm not sure of your question. You can use HSRP between Ethernet interfaces going into the same switch. See below:
router 1# config t
router 1# (config) int e0
ip address 1.2.3.2 255.255.255.0
standby 1 timers 3 10
standby 1 priority 105 preempt delay 300
standby 1 authentication 1020301
standby 1 ip 1.2.3.1
router 2# config t
router 2# (config) int e0
ip address 1.2.3.3 255.255.255.0
standby 1 timers 3 10
standby 1 priority 100 preempt delay 300
standby 1 authentication 1020301
standby 1 ip 1.2.3.1
2. If you have two data circuits, one per router, there is redundancy for each router.
