OK, some quick info for you here.

pH isn't important unless you are planning to breed them.
Hardness will bother them but it depends on what your parameters are.
Again, you will need soft water to breed them. I don't test my water
parameters, I use cardinal tetra's and rummy's to act as indicators, when
they look ill, or the rummy's loose colour in their noses's it's drop what
i'm doing and change the water.

A pair, not a good idea, they are schooling/shoaling fish, IMHO at least 6.
And buy them small, that way you have an idea how old they are, and will
appreciate them more.
Other fish:
stick to smaller fish, and semi docile
south american tetra's: Black neon, neons, cardinals, rummy nose's.
south american cichlids: Rams (gold/blue), angels (make sure they are
smaller than the discus)
as far as gourami's go I'd stick to the dwarves

also check out the discus web forum

http://www.awforum.net/discus/

"Kev" wrote in
.com:

My wife and I have really gotten into fish the last 2 years. we
currently have a 55g. community with asst.
garumis,..swordtails..tetras...ect..then we added a 120g. that houses
2 ,8 inch Oscars,..2, 6 inch tinfoil barbs,..and a couple of channel
cats...both tanks are a combo of live and artificial plants..Now we've
bought a 220g "dream tank" it's equipped with 2 Mag. 350 pros. plus a
diatom for polishing..It's been set up about a week and is cycling
nicely using a big goldfish to help it along...it's decorated with a
huge lava rock, some driftwood a castle/fort type of thingy and
assorted artificial plants and of course, bubbles...While checking out
the different fish stores in our area we found some beautiful blue
discus about 6 inches in diameter..but they want about 80.00$ a piece
and we would want at least 2 to start with..now for the
questions...before dropping another chunk of change into this tank
what else should I know about keeping them?..What other fish can
safely be kept with them?..where should my "stats" be? i.e.: PH GH
ect...also lights...and temp?...Any insight would be greatly
appreciated...Thanks