I'm looking for a method to convert compressed video files (like h.264) into uncompressed formats for editing.
What are the best options to look at?
The answer to your question depends on the software you will use for editing.
Uncompressed RAW video is rarely used for editing for performance reasons. If you have actually recorded your media in 10-bit RAW format (some cameras can do that), then it can be subsequently used for processes that require as much colour information as possible (colour grading, for example).
Modern non-linear editors can be capable of working with H.264 (see Adobe Premiere and its Mercury engine), but you waste a lot of processing power that way.
At the time of writing, the most widely used codecs in the broadcast industry are:
So depending on your operating system and software you may want to transcode to one of these codecs and then re-link your edit to the source H.264 files, to ensure that you get the maximum quality.
Additionally, if you don't have a powerful machine for video editing, you can convert your media to a low resolution codec (to make the edit with it), to later re-link the sequence to high-res media. This process is explained here