how to plumb new basement bathroom?

[spikefishduo]

I would like to add a bathroom to the basement. I have already broke up the concrete to find existing plumbing. I have 3"cast iron under the floor. Here is why I a looking to install:
Shower (small stand up unit maybe 36*34)
Stool
Bathroom sink
Washing machine drain.

I have an attached photo. Shower was planned in corner, removing stack and tying into existing 3"cast with
Floor drain
Stool next to where washing machine is now,
Sink placed where existing pressure tank îs, and washing machine drain next to sink

 

[spikefishduo]

An ideas on venting greatly appreciated