Basements, Attics and Crawl Spaces - Dehumidifier for basement

I have a 30' x 60' basement with poured concrete walls. I have been running a dehumidifer in the basement for the last 9 years. Recently my wife found some older furniture with some mold on it. It was towards the back of the basement. As luck would have it, my dehumidifier stopped working this past weekend. I need a recommendation on a good quality replacement dehumidifier. I'm fairly certain the one I had was way too small, as I purchased at menards 9 years ago. Is there one that may somehow attach to my furnace or should I just get a stand-alone unit? Also, I have a sewage pit in my basement for a future bathroom. I found about 12" of water in it over the weekend. I can only assume it's getting ground water coming in around the drain pipe installed by the contractor 13 years ago. This is also probably contributing to my mold problem. Any ideas how to fix this or should I just get a submersible sump pump and keep the water pumped out of it?
Thanks in advance.....Dick

Dick: Any standing or exposed water in the basement will present problems, and NO dehumidifier will help. I'd figure a way to get rid of it, even if it does require a sump pump. In your space, also (1800 sf), that's a lot. How much space does your dehumidifier claim to handle. It may take more than one. How do you deal with the condensate? Is it pumped out of the basement or do you empty it daily?

yes.. I agree... I think I will install a submersible pump to keep the water out of the sewage pit.
Regarding the defective humidifier, I have no idea how much area it was designed to cover, but I have a feeling it was way undersized. Do you have a recommendation on what I should be investigating for this? One thing I forgot to add it that I do have air conditioning throughout my house, including the basement, so that helps a bit. I just checked my rh and it read about 56%.

Regarding the condensate, I would empty it about every 3 days.

Every three days isn't bad at all. I drain mine directly into a floor drain, so I have no idea how much it is moving, but it runs intermittently so it must be doing the job.
As far as how much dehumidification you need, since one area is seemingly neglected, I would probably run two for that large an area. I bet you will see a difference in the emptying duties on the other one, as there may be more humidity in that particular area.

This is the leader in residential dehumidifiers. Santa Fe Classic Dehumidifier (http://www.thermastor.com/Santa-Fe/)
It will handle your basement. It also can be ducted into your HVAC equipment. I sell these all the time when we do mold remediation.