Clo - See my thread a few items down the page called "Just Returned from Mariner of the Seas". It has links to a review and pictures that will help answer some of your questions. The Mariner is a sister ship to Voyages and is nearly identical. I highly recommend the junior suites, and specifically the ones on the "Hump". You will see from the pictures that the bathroom has a tub instead of just a shower. Also, the "hump" is where one bank of elevators is located, but the elevators face the center of the ship - so noise was never a problem.
Also check out the thread a few items down called, "Mariner "Hump" Cabins 8318, 8320, 8620, 8618". But I recommend the ones on deck 9 - which are junior suites. I understand the ones on deck 8 are just balcony cabins.
We were in 9318 on our April cruise and loved it.
If you use a local travel agent, as other have recommended, they will be able to steer you to the best cabin for your needs and comfort.