Congrats on all your travels. YES, there is a customs station on the Brazil side, but they are very good, and you could ask perhaps for a "salva conducto" (sorry, that's in Spanish - don't know the correst term in Portuguese..) which gives you one or two days just to get over to the bridge.
If you are going to spend the night over in Foz, I recommend the Youth Hostel out towards the airport. We stayed there 4 days and met other riders too. It should be in your guide if you have one. After the Brazilian customs you hit a 'T'. Turn RIGHT towards the airport and it will be about 3 km off a road on your right, past the big hotels.
The only other way is to head back to Posadas (300 km) and cross over to Encarnacion: View Larger Map
View Larger Map
If you are trying to sell, Asuncion might be better than Ciudad del Este which is a mafia nest, and this crossing (besides the great sites to see near Trinidad) might be a better option..