I'm really surprised that you can't find an L293 or equivalent locally (which is where, exactly?); they seem common as dirt to me (then again, I am in the States - there are probably surplus dealers here who have 55 gallon drums full of 'em).
Have you considered making your own h-bridge from some TIP120 transistors or similar? It would teach you a lot about how h-bridges work, plus the parts would probably be easier to source. If you use bipolar transistors, you can build an h-bridge from all NPN, or a pair of NPN and a pair of PNP (which is more efficient than an all NPN). Going with mosfets is doable, but an all N-channel h-bridge is difficult to create without a high-side driver or charge pump (thus, going with a pair of n-channel and a pair of p-channel works better - if you can find a complementary pair of p-channel mosfets).
Something approaching a single bridge of a L293 would be to use a pair of 2n2222 (NPN) and a pair of 2n2907 (PNP - complement to the 2n2222); this will run small DC hobby motors fairly well. You would of course have to manage things to prevent shoot-thru, as well as implement other controls (and you wouldn't have any form of overheating or overcurrent protection), but such a small h-bridge can teach you a lot about such design (and if you blow parts while building and testing it, you haven't lost a bunch of money).
There are plenty of tutorials and examples of such small transistor h-bridges out there on the internet - so consider it as a possibility, perhaps.
