Nate,
Yes i understand it will make sense to run a routing protocol. I am attaching the full config of the srx-1500. I was thinking on running two eBGP connections. The SRX-1500 will have two ebgp neighbors one with MX-primary and the other one with MX-backup. The ebgp connection to MX-primary should be establish over ISP1 and the connection to ISP2 should be over ISP2. The site is in puerto rico with no the greatest reliable internet, so i was concern with BGP flapping because ISP1 having delays or jitter. Also, the site internal network require local internet and just traffice to HQ internal network go over the tunnel.
Thank you for taking the time to share your experience!!
Nils.