I can probably help with memory upgrades, I have a number of o2s and lots of parts here including 2 of the much sort after R12K machines. Though shipping one across the pond is probably too expensive.
As for lightwave, someone else is going to have to help you with that, if you see a machine with it preinstalled *AND* it has the required licenses installed it probably worth buying as the software is the difficult and expensive bit to get.
Gaz
