Having traveled through Mexico, Belize and Guatemala you won't have a problem with Suzuki parts at all. I also talked with some of the folks here in the marina (I'm in Guatemala at
www.monkeybaymarina.com) and they said no problem with suzuki in Honduras, Costa Rica, El Salvador, Panama or Colombia. Took a look at their international web site, dealers world wide including South America, New Zealand and Australia to name a few places.
Here in Guatemala Suzuki is one of the most popular brands. One thing I learned when we arrived last summer was that, even though Yamaha and Mercury are very common here, they are not the same as the ones bought in the US. The Yamaha and Mercury outboards bought in the US are different models than those sold here in Central America. Though there are many parts in common not all are the same. We've known boaters here that have both, particularly the Yamaha, and they have difficulty getting parts. Not always but sometimes, depending on the part I suspect. If you put a Yamaha 15hp bought in the states and place it next to one bought here, they are even physically different, same with the Mercurys. Doesn't seem to be an issue with Suzuki and Johnson.
We don't see many Nissans or Tohatsus, usually only with the cruisers. On the flip side the Yamaha's and Mercurys run quieter. In the past four years I've owned a Yamaha 6hp 4 stroke (great motor but undersized), a Mercury 8.0 2 stroke (excellent but still underpowered for what I wanted), a Nissan 9.8 2 stroke (hated it), a Mercury 9.9 2 stroke (my favorite), a Johnson 15 2 stroke (nice, but idles rougher than the others, loud), and now I have a Suzuki 15 2 stroke (nice). Now I know that's a lot of outboards in the past four years, but we've upgraded to match a new RIB, one for the launcha we bought here on the Rio, and when someone offers us more money than what we paid for the darn engine how can you say no?
By the way, the most stolen outboards here are Hondas. they are not common here and the theives love them.
Hope the info helps.
damon