*Same answer
Lizards:
Varanids (dwarfs) Tom, they seem to keep a place in the market. Try and get some of the rarer ones on the market such as V. gelleni or V. storri. I would avoid the large varanids as the market is already sturated with $50 WC savs. Plus they take up too much room.
BTS are nice easy captives, avoid the Indo varieties and focus on the Northerns from Aus (I can point you to good breeders over there that may be able to give you a hand with a colony). Live bearers so no egg incubation.
Knob-tailed geckos are easy enough to care for and command a good price on the market. Still fairly rare so I'm sure you won't have a shortage of buyers as they seem to be growing in popularity over there.
Strophurus geckos are quite pretty, again still a bit rare in the market and not to difficult to care for and easy to move.
Diplodactylus geckos are also another sought after australian gecko over there. Small easy to care for don't take up much room at all yet command a good price.
Chams are good always popular not too sure about the care but their live bearers so one less thing in the incubator.
Snakes:
There's a massive Morelia market over there, particulary for JCPs and Bredli, Easy snakes to care for and do well in standard 4x2x2, no special requirements in humidity or any other specialised husbandry needs being their Oz natives their tough as nails.
Aspidites are another popular snake species over there (womas and blackheads) again no fuss captives.
I would find the species that are popular yet hard to get and easy to care for first. Keep the over heads low for the first few years and target species that you know will move in the blink of an eye. Avoid an "overly" saturated market with breeders. Avoid species with overly specialised care as you would be spending to much time fixing husbandry rather than focusing on the business. Target species that can live in "rack" systems. I would avoid any aquatic species till you get more established. I would try and keep the proportion of "diurnal' species low for the first few years at least until the business is regularly turning over a healthy profit. The over heads on lighting system and power cost would be lower that way.
Side note start lookingh into alternative lighting systems such as hologens (this will keep the bills down). Safe CFLs for the ones that require UVB. A good supplier of foods, never too early to start looking into this as well as breeding your own to keep overheads down.
Most importantly a secure place to keep all the specimens in. Start designing a large scale reptile room, hatchling racks, incubators etc.. etc...