Veral makes the best molds and designs and his are lathe turned, so they tend to be more perfectly round than others. But you do pay for that, and if he is outside your budget,
NEI has conventional cherry cut molds, and one of their existing designs may fit your purpose? They have a 350 grain truncated cone .429, and a 380 grain in .451, though I would call and ask the lengths to check their compatibility with your rifling twist rate before buying, to be sure you can stabilize them OK? The Miller twist estimator is available in Excel from for free download from my file repository,
here, and in an
online version at the JBM ballistics calculator site.
Mountain Molds lets you design your own. I've never had one of their molds, so I can't address the quality, but I've not heard any complaints, either. I haven't looked at it closely enough to tell whether it will let you design a tumble lube bullet like RD's or not?