Hello Ryan --
There are lots of livebearers out there, you just need to know where to look. Endler guppies are perhaps the livebearer-du-jour, but whether or not the stuff sold as Endler guppies in most shops actually are true Endler guppies is a topic for discussion. Suffice it to say, these are small, 'wild-type' guppies very different to the standard aquarium-bred guppy.
I keep halfbeaks (see
here), several species of which are quite widely traded in the UK. The 'Celebes halfbeak' is probably the easiest to find, and shipments of this fish usually consists of
Nomorhamphus liemi, but other species, such as the red-fin halfbeak,
Nomorhamphus ebrardtii sometimes get included as well. I believe
Nomorhamphus ravnaki is also traded as the Celebes halfbeak, though less commonly. More than one species of
Dermogenys is sold as the 'wrestling halbeak' or 'silver halfbeak'.
If you're in London, places like Aquatic Design Centre, Wholesale Tropicals, and Wildwoods are definitely worth visiting. You can keep track of their stock, to some degree, by visiting
tropicalfishfinder.co.uk, though I strongly recommend you call them up to confirm they have the fish listed. Last time I was in Wholesale Tropicals, a couple of weeks back, they had a bunch of neat livebearers including
Heterandria,
Girardinus,
Ameca, and
Alfaro spp. Do bear in mind that none of these fish is "cheap" in the way guppies are, so budget two or three pounds, at least, per fish.
Halfbeaks at least make good community fish, but female
Nomorhamphus liemi are big fish (~10 cm long) and easily able to eat a whole male guppy if they chose to. Having said that, mine live with cardinal tetras and show no interest in them, and the only time they have eaten their fry was when I was on a 3-week vacation and the neighbour was feeding them only once every two or three days.
On the one hand, halfbeaks can be difficult to look after, and mortality can be high. I've made some silly mistakes and lost fish in the process -- e.g., not covering the tank while working on plants or the filter, only to find a dead halfbeak on the carpet afterwards. However, once settled in they are hardy and fun to watch. Breeding them isn't at all difficult, and the fry are very, very hardy. For example, while I was on holiday, the breeding tank practically dried up, for reasons I don't fully understand. Anyway, the heater cracked and died, and the filter stopped. When I got back, the water was about 2 cm deep and freezing cold. Though small and hungry, the single halfbeak baby I had in there, barely 15 mm long, was just fine. I've also rescued a baby halfbeak from the point of death -- i.e., white, unable to swim, gasping -- and now its grown up fine except for a twisted spine, which may or may not be related to its sickness.
Cheers,
Neale