Siham,
unfortunatly I am not so experienced with batch tempering machines. I work in a company that can produce continuous tempering machines.
The main difference is that heating and cooling (in one word: tempering chocolate) are made contemporary, in a continuous temperer. While in a batch temperer you have to melt and then temper. For what I know (because till 2003 we used to produce one batch tempering unit), you have to use the tempered chocolate in a determined time to be able not to loose the tempering curve. While in conotuous system, chocolate that is not used go back into the melting bowl and it is heated again.
Batch tempering machine are, in general, less expansive than continuous. I am not sure this difference in price is kept if you start considering the enrobing features too.
Again, everything depends on you. Your production (continuous temperer are more productive) but budget too.
Giuseppe