generally it's recommended to go with the batches over single old episodes. Single eps aren't easy to keep seeded - it eats up too much system memory to seed 80 torrents, especially when you can seed 8 with greater effect.

You might want to try using a client like azureus and picking the file you want to download. I hear that works pretty well for some people. You should (I think) be able to point it at the part of the episode you've got and it should (hopefully) resume it from the batch, but .... your mileage may vary.