Papaya & Cali Indica x Big Bud

I've been doing some searching because I have some questions about some gifted seeds. Mostly the issue is with the Papaya, as the Cali Indica x Big Bud seeds sprouted well (80% success rate thus far). The Papaya, on the other hand.. two out of five seeds have sprouted. A bit more disappointing, but I'm still working on those other three. I've placed them on a small heating pad set low. Only problem with the new ones is they turn themselves off after two hours of continual use.

So, should I expect the Papaya to be a more delicate plant overall? Since I'm not getting great germination I'm not sure whether or not I'll be able to breed this strain to keep at least one pure line. If not I will be keeping the pollen and crossing it with my unknown (guessing an Indica strain, though) bagseeds.

Also, does Papaya not lend itself to outdoor growing?

Just a bump, I'm having one HELL of a time with the Papaya. Doesn't want to germinate, is slow to sprout. Is it too cool in the mountains at 38*lat.?

Edit: Ok, often, the answer you get depends entirely upon the question you ask. So, I ask, what do folks do who have seeds they want to get germinated (limited supply), but are having a hard time with?