For my money the P100... I've only got experience on the P60se, but:

1) newer technology in the P100
2) smaller components and less weight for a little more thrust, and more install options
3) only one input fuel line, and only kero start;-) ie, simpler

Now, if money is the issue, and you save lots of $$$ then by all means the p80. I would only do that if I was going to save like 500.00 or more on a p80 vs a p100
my .02

Z