At the point, an "Instant Death" seems to be the most appealing option out of the four. We all die in the end and I can only imagine that even natural deaths come with some kind of discomfort. Being able to check out in the less than a blink of the eye is a huge boon when you really think about it. Unless infinite money allows me to purchase a time travel paradox breaking time machine that I can abuse, it cannot buy me happiness--distractions for certain, but never genuine happiness. I am fortunate that my family is already loving, so that option doesn't really change matters all that much beyond making our interactions a little more healthy. Had I been presented this question 10 years earlier, I would have chosen to be cured of all of my illnesses, but now, even if I were to wake up perfectly healthy tomorrow, it is sadly too little too late.
Instant Death it is.