My advise is that, try out as many guitars as you can, find the one that plays comfortable left-handed. Fored is right about the knobs getting into the way (especially during gigs). If you're going for a guitar with tremolo system, you'll have to learn to get used to it. Depending on preference, some people actually prefer the tremelo to be on the above (example SRV). Another thing to take note is the cutaway. Best is to get something of the same cutaway, eg, SG, Ibanez Artiste series, or no cutaway (Flying V), unless your fingers are darn long and can reach the last fret without difficult. The body contour might also be an issue and can be uncomfortable to play with.
I've had my share of experimentation cos I'm a lefty as well. My first electric's a righty Ibanez Artist. Great guitar but with the edge stabbing into arm and accidental knob-turnings, I've found lefty guitars to be so much more comfortable. I've also tried to do a 'Hendrix' by buying a righty strat but I couldn't reach the highest frets due to the cutaway. The strat knobs were rubbing against my arm as well...so, it was sayonara to righty guitars *lol* Now I only look for lefty guitars :lol:
Basically, these are just some of the things to take note of if you're really going for a righty guitar. Otherwise, I'd advise getting the local shops to help you import a lefty guitar or order it yourself from some online stores.