For anyone looking on the topic.
Tank costs about 150-180 to "buy" (unless you have your own tank that you want to keep, most places will swap tanks out with filled ones so you never really keep the same tank) and about 70 to rent for the year.
I ended up borrowing a tank from a supplier, he said if I could get it to him on monday he wouldn't charge me for renting the tank over the weekend, just have to pay for the fill. It was about 60-70 for helistar which is their helium, argon, co2 or what not blend.
So I bought 308L wire and went to town. Stainless does require you to be quite a bit closer to your welding material, and it seems like it likes to go pretty slow or at least run with more amperage, other then that I didn't notice too much of a difference. The way the mounts were moved made it feel flimsy even with triple pass welds whenever I could, so I ended up welding in some mild steel reinforcements with the stainless mig setup.
One thing to keep note and this applies to all welding is that heat really is a consideration. I had the gap for the bushing shrink enough to the point where the bushing wouldn't fit anymore, so I ended up hammering it back out. Afterwards I employed an all thread with some correctly spaced nuts to help keep the parts apart while I put in the reinforcements.
Thanks grannyknot for letting me bounce my concerns and your advice.