In general for cash games (NL, anyway) I find that 20 of the lowest denom and the rest of the buyin made up in the next denom chip works well, 25c and $1 in your case. I'd do rebuys with either more $1 chips or $5 chips, depending on what was already in play. I like having a lot of chips as well
You'd probably know best about how many rebuys in general you'd expect but if you're using a set for both tournaments and cash games, you'd have other denoms you could use for a higher value in cash games, so running out shouldn't be an issue.
I've spent way too much time fiddling with both a spreadsheet and the Chip Forge and Factory...
