Balance 710 failover to same ISP

Hi Guys
Can you advise if this is the best possible solution? We have a Balance710 configured in drop-in mode.

We have a site with four links.
Two links to ISP1
One link to ISP2
One link to IPS3

There is a /24 public subnet routed currently via WAN1 to ISP1. We want to ensure it fails-over to WAN2 to ISP1 and the /24 routes through this link without NAT being applied on the interface.

Now from my understanding, the peplink cannot do this… So we’re thinking to drop a cisco router on WAN1 (drop-in-mode) and implement EIGRP to handle failover on the two links to ISP1 such that the /24 remains route-able.

Is this the best situation?