I can appreciate how torn you must feel. I went through a similar decision making process about 1/2 year ago. However, for me, it wasn't about the availability of benefits. Rather, one position included a very respectable salary with a large, stable organization. There were also other people performing similar tasks, so if I did became sick again (I've had one attack), there would be others to cover for me. The other position had a small base salary (about 1/2 of what the other salary offered), but seemed that it would be much more fulfilling and had a significantly higher upside (both personally and financially).
Part of the decision process I toiled through involved "what would be the safest" vs. "i don't know how much time i have...can i really afford to pass up something that could be really fulfilling?" I went back-and-forth for about a month.
I ended up breaking things down to their most basic level, based on best case and worst case scenario. I am not married, but I have family members that I can count on that are pretty well off financially. We don't have universal health care where i live (in the US), but my state offers a decent insurance (for a reasonable amount) and nobody can be denied. Thus, I have a fall back in the worst case scenario.
You may want to assess, who and what do you have to fall back upon if you get sick. Also, what would the differences be in your quality of life between both jobs, based on both the best and worst case scenarios.
Before I end this long and winding entry, I am sorry you are even in this position. It really sucks that we have to make these types of decisions based on this incredibly annoying disease.
Best of luck with your decision,