Policy Based Routing on Juniper SRX320

So, I got a gre tunnel (used to be an openvpn when my router was a linux box) from my local juniper srx320 ( connected to internet via a PPPoE with a dynamic IP ) to a location from which I route a /29 ( from a bigger /24 ) on a linux machine. The issue I get with using most online tutorials is that the session gets async because the "public" IPs I route are binded on the same interface I have with my local lan. I can easily change and use vlans or anything else if needed. The reason of the tunnel is to get a static IP from an ISP I work at to home where I have a dynamic IP. I used to have openvpn before ... and it worked .. because of packet-based routing ... Now flows and sessions and zones and policies caused a brainfsck. Bonus ( double the money ) to someone who jas knowledge and can help me setup strongswan on the remote linux box and migrate from the gre to an ipsec tunnel. Again, I'd like to actually understand what happens so I can replicate/debug if needed. I need about an hour or two tops probably with someone to remote screen which can explain to me step by step how to do the pbr. I'm gonna do it under your supervision. Audio is required. Video will be a remote screen to me. I'm a networking guy new to the "zone based firewalls" security appliances .. I do know how packets are supposed to be routed and how filters work and vlans and stuff, what I lack is a little bit of juniper's internals on how it processes flows and sessions ! PLEASE PLEASE PLEASE ask for any and all details to make sure you get all the details before posting a bid. I can draw a map of the architecture if needed.