I ended up solving the problem by getting a little creative. The three DSL modems now wire directly into a Mikrotik RB-750 router, which establishes the PPPoE session through the 3 modems and bonds them together, then shares the resulting connection with my server. I had to get a little more creative because I host a static /28 subnet on my server, which used to handle the connection, since the server itself would choke when I try 3 lines at the same time.
So… The router establishes the PPPoE session and receives the 69.xxx.xxx.6 IP address. From there, the router hosts the /30 subnet using 69.xxx.xxx.177, with the server on 69.xxx.xxx.178. I had to add in a routing rule because my ISP will only push the next hop for all my routing to the IP address of the PPPoE link. So, a few tweaks later to add a routing rule to tell it that if the destination is 173.xxx.xxx.80/28, forward the packet to the server at 69.xxx.xxx.178 as the next hop. Once I got that all setup, I was back in business. 
As for my laptop, it's a little more creative. I now only use two network cards in my server. The first network links into the Mikrotik router in which to get its internet connection, then shares it on the second network card. The wiring then leads from the second network card to a 16 port 1000mbit switch, which all the devices in the house hook into. Also, this main switch is where I have another line link it that leads out through the outside wall, down into the ground, where it then runs about 200' or so underground to the trailer. It then magically reappears above ground behind the trailer and leads inside to the WAN port on a Linksys WRT610N router mounted to the inside of the one wall. This router is separate from the D-Link DIR-605L router that sits on top of the entertainment stand in the house to run the main WiFi.
It's a little complicated by design, but at the end of the day, I was more concerned with making sure THAT everything works, including the ability to stream seamlessly in 1080p HD, rather than focusing too much on HOW everything works. 
See…. Out here, we only have pre-Y2K legacy DSL on copper. We don't even have FTTN (Fibre To The Node) out here because the Oligopoly sucks. So... Because of this and because of the fact that I am a little more than 5kms away from the SLAM, the best that I can get and remain stable with is a 4032/800 profile, which only gives me about 3.2 to 3.5 mbit down, and a mere 0.6 mbit up. Once the Mikrotik router bridges the three DSL modems together using MLPPP, I magically end up with a connection that runs on a single line that can handle between 10.2 and 11.1mbit down (depending on network load levels in the neighbourhood), and consistently gives me around 1.75mbit up.
As for the laptop and all the handheld devices, they connect VIA WiFi, except there's a bit of a catch... The connection is routed through the Linux box as my firewall, which then if permitted, allows the connection to pass through to the Mikrotik router, where it is then split into three different segments before leaving on the 3 DSL modems, only to be reassembled on the other end by my ISP. Even the DHCP is run through the server, so quite literally, if the server goes down (which it did recently), EVERYTHING stops working, including the home automation system which allows us to do things like lock or unlock the front door from our phone, check out the IP cameras, change the thermostat settings on the furnace, etc. hehe... It's a very custom setup indeed.
