I have a copy of the six suites that's transcribed into more bass-friendly keys by Samuel Sterling (Edition Peters). I've found only a tiny fraction of them to be playable on electric bass, given my chops.
I've dug up some of the cello music that I played as a kid. There's a nice set of six chorales transcribed by Pierre Fournier (International), that are lovely, and not intended to be fast.
There's huge amounts of beginner-to-intermediate cello literature out there.
About the famous first prelude, I have yet to hear a rendition on electric bass that really sounded musical. The closest seem to play them in the style of classical guitar. Like my daughter said about the violin part to Don Juan, "everybody can play the notes, the trick is making it sound musical." I think the second prelude is long but vastly more playable if you're looking for something to start out with.