Heliconia seeds are notoriously difficult and slow starters. The best method I've found yet is to soak them overnight in water with a drop or two of hydrogen peroxide, then suck on them (yes, put them in your mouth) for about 5 minutes while contemplating the lovely plants they'll become, then pop them into a bit of moist peat in a ziplock baggie and forget about them on the top of your fridge at the back (where it's nice and warm). 5-10 weeks later you'll see sprouts if the seeds are viable.
For passionfruits, soaking them in the juice of passionfruits for a couple of days before sowing is best, but you can also get away with soaking them in lemon juice. Then plant into moist peat or vermiculite (your choice), and once again, forget 'em on the top of the fridge at the back. 3-5 weeks to sprouts.