Nac-pro, here's one within your budget:
Veleiro FAST YACHTS FAST 395 40 pés 1989 - Usado
These boats have a good reputation in Brazil as a fast cruiser. It's a Frers design.
If you can go over your USD100K budget you might want to look at a Bramador 34 built in Argentina. You can get an almost new one already equipped for a bit more. The Bramador is a nice boat.
Boat Show ::. Mercado nutico: barcos, lanchas, jets, veleiros, escunas, inflveis, jetboats
The video link above is a delivery from Buenos Aires to Rio, bringing a Bramador 34 to the Rio Boat Show. It also serves as a reminder that the stretch of coast from the River Plate to Florianopolis, Brazil can be a pretty tough patch of water! Even Slocum managed to lose a boat here once.