Thanks for the suggestions! I'll take a look at some bond funds. My family had some good luck with CDs in the past few years (all of ours had ~3-4% interest), but there isn't as much out there.
My plan is to build up my 401k and a couple Roth IRAs in parallel. Assuming I can live off of ~$10k/year, I would take a SEPP distribution from one of the IRAs, and concurrently rollover ~$10k/year from my 401k to the other IRA.
Currently, ~$10k/year is sufficient for me since I have no debt and don't pay for housing. If that changes, then it could be a stretch, but it depends where I am. Excluding housing/utilities, I maybe need ~$6k/year for the essentials (food, transportation, insurance, cell, maintenance, random toys). If that changes then I'll need to increase the amount I've saved in the IRA I'm taking SEPP distributions from, but I don't think that'll happen given my living situation.