Reddit reviews Petronius: Satyricon; Seneca: Apocolocyntosis (Loeb Classical Library No. 15)

So by saying that you don't want the facing translation that you are specifically not looking for the Loeb version. I looked and Archive.org does not have an old critical edition from what I could find. This is the best I could find, but we all know that 1743 was long before a lot of good textual work for all of classical literature was done. Here is a modern critical edition for a surprisingly reasonable price, however.