secretagent wrote:
"Any supplements other than the ones mentioned that are most haves or must avoids?"
Mr. Agent,
Can't think of any 'must avoids'. Some of the supplements may not be your particular cuppa though.
I'd grab the S:1889 Basic Rules Book (duh) plus 'Soldier's Companion' and 'Ironclads and Ether Flyers' (IEF). They are all text based rules.
'Sky Galleons of Mars' (SGOM) was rules and a set of minis. It's good but IEF covers the combat bits, plus construction rules.
There were a number of published adventures. IIRC, two were volumes of stand alone multiple adventures, 'Tales from the Ether'. They'd help you get a feel for the setting and cover some of the places just touched upon in the basic rules; Mercury, the Moon, the orbiting heliographs, etc.
The other published adventures are campaigns; a series of linked adventures and encounters moving towards a denoument. There was one about Mars' Canal Priests, another concerning Hill Martians, and so on. They're all good but not entirely necessary.
Finally, there was a board game! It covered a rescue mission mentioned several times in several S:1889 timelines - the rescue of a kidnapped ambassador and his daughter from the clutches of a bestial High Martian king in his fortress tunneled out of a butte; an example of the infamous High Martian 'kragg'. Each player had a charecter; adventuress, inventor, rogue, vicar, etc. with different victory conditions; escape, loot, examine artifacts, rescue damsels, etc. Play was on a map made up of player placed cards, so the floorplan of the kragg changed each time.
Hope that helps.
Sincerely,
Larsen