If the latter, then shimano hubs are fine. They have very good seals, but dismantleable and loose ball so you can clean and regrease as necessary.
In terms of a BB, basic cartridge ones are fine. But basic loose ball ones are shit as they have no seals. Good looseball BB's are hard to find, the only decent ones that you can get hold of tend to be the track and road ones which have poor or no seals on them. Ive seen old ones aimed more at touring bikes that had very good seals.
For fixed or gears?
If the latter, then shimano hubs are fine. They have very good seals, but dismantleable and loose ball so you can clean and regrease as necessary.
In terms of a BB, basic cartridge ones are fine. But basic loose ball ones are shit as they have no seals. Good looseball BB's are hard to find, the only decent ones that you can get hold of tend to be the track and road ones which have poor or no seals on them. Ive seen old ones aimed more at touring bikes that had very good seals.