I would get one of the G3/233 iMacs -- you can install panther on them without any modification. The G3/400 would be nice if you're confident in your ability to repair it, and that would run Tiger without any modification, other than adding a hard disk and maybe some ram.
There are a wide variety of little problems with OS X on beige G3s, including partition size problems, massive performance issues, etc.
If you intend to get an upgradeable machine, before you buy it, research very carefully the cost of upgrading that older machine versus the cost of just buying a newer machine (which will have better performance anyway.) -- even with an 800MHz G4, a beige G3 will be limited by its 66MHz bus, whereas a native G4/533 tower will have a 100 or 133MHz bus.
And there's a certain point about 75% of the way through the G4 lineup, at least here in the USA, where you may as well get a new intel-based Mac Mini: http://www.colombo.com.br/produtoDetalhe.do?produto=150063&descricao=Mac+mini+MB463BZ_A+Core+2+Duo+(2.0GHz)+1GB+RAM+120GB+Apple
though for $2700, I can see how a G4/533 for $200 is a downright steal compared to american pricing.
There are a wide variety of little problems with OS X on beige G3s, including partition size problems, massive performance issues, etc.
If you intend to get an upgradeable machine, before you buy it, research very carefully the cost of upgrading that older machine versus the cost of just buying a newer machine (which will have better performance anyway.) -- even with an 800MHz G4, a beige G3 will be limited by its 66MHz bus, whereas a native G4/533 tower will have a 100 or 133MHz bus.
And there's a certain point about 75% of the way through the G4 lineup, at least here in the USA, where you may as well get a new intel-based Mac Mini: http://www.colombo.com.br/produtoDetalhe.do?produto=150063&descricao=Mac+mini+MB463BZ_A+Core+2+Duo+(2.0GHz)+1GB+RAM+120GB+Apple
though for $2700, I can see how a G4/533 for $200 is a downright steal compared to american pricing.