you will love them. My bedroom is devoted to them. I have 12 different species, ap. australe orange, ap. australe ebt 96/27, ap. striatum, chromo. bitaeniatum (ijebu ode), fp. gardneri N'Sukka, fp. gardneri lafia, fp. scheeli, fp. walkeri kutunse, fp. sjostedti (blue gularis), fp. filamentosus, notho. patrizi. Those are the pure strains. We also have Fp. gardneri czech republic, which is an aquarium strain.
They are very easy to breed, they are not picky. If you are going to collect the eggs though, make sure you give them the right medium to make collecting the eggs easier for you.
And not all killies have short life spans. If you get into the non annuals, you get fish that will live 2-3 years, if well taken care of. All of mine are non annuals, except for the notho patrizi.
Check out the american killifish assoctiation. They have lots of useful information.