With respect to heat one possible solution is to use heatsinks or make the copper area below the chip as large as posible, for example using a power plane. Also another solution, (more costly) is to use forced air flow, i.e. fans. I'll try to make a pcb for you but right now I don't have too much time. Yosmany325. If you can take a look to L293D datasheet.
Ok Yosmany,only make the copper area below the chip as large as posible without fans or heatsink and we 'll see.
Only add when you have the time to the previous pcb all the l293d connected to pic with sockets for outputs like schematic and the res and led to dc regulator.
Thanks