Personally, I would hold off on getting in the penguin-suit until you've completed your check-ride...it gives you something to look forward to, and there is no way you can feel "fake" if you've earned it LoL...but anyway, all you really need to jumpseat is business-casual. And I would not expect the comany to put you up in a hotel for an observation flight - try to catch and out-and-back.

Finally, during the observation rides, I would persuade you to not attempt to memorize the flight crew's flows, callouts, etc...Line flying is a whole 'nother animal from Flight Training, and you don't want to get too confused/overwhelmed. Take that opportunity instead to see the bigger picture - where everyone is at what times during the pre-flight, when the paperwork shows up, when you push, how you push, etc...the 121 procedures are what they can't teach you in Sim.

And like tsween said, jumpseat in a buddy's sim-training...that's where you'll learn the most for your checkride.

...Elvis...