If you are in a hurry, here's the short solution for texts, minus the explanations:
1) Purchase Helen McCullough's Anthology of Japanese Prose.
2) Purchase Helen McCullough's Genji & Heike, unless
a) you are the type to put in some additional work for extra credit. In which case purchase ....
... if you want to try out Genji in its full 1,000+ pages either Edward Seidensticker or Royall Tyler's translation. Because of the setup of the class, Seidensticker is more convenient. Both are excellent, however.
... if you want to try out Heike in its full 400+ pages Helen McCullough's translation. No other.
b) you really don't like reading onscreen: there are about 150 pages of such reading unless you purchase Seidensticker's unabridged translation of Genji. You can purchase Tyler but since this option is about convenience you might as well make it completely convenient by using Seidensticker. Either works, though.
Explanations:
Many of the texts for this class are PDF files that are available on bSpace.
However, there is substantial reading assigned from Helen McCullough's Anthology of Japanese Prose. In my opinion it is impractical to complete the readings using the reserve copy, or to piece together all the various portions through other sources. It is in too many bits and pieces to do that easily or time/cost efficiently.
Finally, we read very large excerpts from The Tale of Genji and Tales of the Heike (300-400 pages in the first case, 250 or so pages in the second). Some might be able to read their in their native language. It will make following class rather difficult, but it is marginally possible. Please be very careful to locate a quality translation, not something from the web. There are some really poor translations on the web. Matching up what is assigned with such translations will be a major challenge.
Regarding English translations of Tales of the Heike: In my opinion the McCullough translation is the only choice for this class. The other full translations are so poor in quality (comparatively speaking) that they are not worth your time and money.
Regarding English translations of Tale of Genji: We read from McCullough's Genji & Heike but I supplement this with about an equal amount of further reading of the narrative. That missing portion must be accessed. I have provided those 150 or so pages as a pdf on bSpace. That pdf is Seidensticker's translation.
You can see what will be required by downloading the pdf from bSpace ("Genji_Seidensticker ...") and check this page that outlines the assignments: Genji & Heike Assigned Readings (pdf). (***The pdf file is not perfect, and lacks the helpful footnotes of a print version. Its only plusses, really, are that it is free and searchable. In all other ways, the print versions are definitely superior.)
If you don't want to switch back and forth between two translations, you should buy Seidensticker UNABRIDGED.
If you want to go the most inexpensive route, just buy Genji & Heike and use the provided pdf file for the remainder of the reading.
If you don't like reading a lot of text (hundreds of pages) onscreen, buy Seidensticker and use only it.
If you find a better deal on Tyler, or just want to read the most recent translation, you can use it but matching up the required reading sections will need a little work on your part.
If you want to read it in full, for general extra credit, the choice between Seidensticker and Tyler evens up. Both have the plusses and minuses but Tyler is best when read cover-to-cover. Seidensticker works better when reading portions. (This is because Seidensticker uses stable character names across the full translation, to help track narrative figures. This is not the practice of the original, however, where characters often are named by their current government post and, as they are promoted, the name changes. Tyler follows the original more closely in this regard. When reading his translation cover-to-cover, these changes are not that difficult to follow. But when reading excerpts they can be very confusing.)