i'd stick with Irix too.
the monitors that they came with were rebranded Sony Trinitron flat tube jobbies. with a VGA to BNC adapter, a BNC to 13W3, and a load of 10base2 "T" pieces, i fasioned a cable that allowed my CV64/3D to drive one.
very nice screens. you can actually get VGA213W3 adapters for them that sort all the sync signals out to the right pins. i think that 2 adapters and 2 cables cost me £40 about 9 years ago. one for the CV64/3D one for the CVPPC.
thing is, that with all this flat panal madness, these CRTs are going for a song. but they were ma-hoo-sive, and had enough shielding in them to protect from a nuclear pulse.
and i dunno what the current draw was when the thing switched on, but it made the lights in my house dim!
the indigo2 isn't a bad machine, you can get CPU upgrades, etc. and just cos it runs at 200 odd Mhz, it still packs some punch :-) max out the memory if you can! Irix will thank you for it

plus its got a wicked little openGL multiplayer tanks game....
i was on the look out for an o2+ with an R12000 :-D