I know it's too late for the OP now, but if anyone else finds this thread on search, then the answer is...
Yes, there is a Suzuki dealer on Av Rep de Panama, but they don't sell spares. For spares they told me to go to the Panamericana Sur on the corner with Av El Derby, near the hippodrome. I didn't actually check this out, because I found what I needed closer to home - there's a useful bike shop in Miraflores that stocks lots of spares on Petit Thouars, cuadra 43.
Hope that helps someone one day!