ENTIRE SYSTEM NEEDED TO SELL

So sorry for your loss. If you are close to Minneapolis, MN I would be happy to sell the gear for you on this site. If it is high end gear it can be sold here. I am also willing to help you with the value of your gear if you are far away. Check my feedback, like to help you during this difficult time. 

Hi may your loved RIP. 

Above advises to sell  locally are great and most useful. If you find high-end store in your area or at reasonable distance of travel, you're likely be successful to consign equipment. I would not 'slice' more than 20% for them. Some of them would like to have 35...50% and they are indeed crooks. Do NOT explain them your situation!! It will only trigger buyer to take an advantage! I would rather keep silent and just ask them if they would like you to consign equipment to them yes-no-hi-bye. 20% on equipment that's worth let's say $20,000 is descent steak for the store and I speak from the retailer's stand point.  So call around and do 'shopping' to choose the best and most honest dealer in the area or within reasonable distance.
 
Internet-eBay-PayPal- etc are not safe unless you use some precautions: 
1. Do NOT sell entire system and list your items separately. Large amounts are harder to deal with in internet transactions especially if your internet selling account is new
2. verify PayPal with money-card purchased from WalMart or ordered via internet such as accountnow.com. These cards are pre-paid and provide you with bank info legit enough to connect with PayPal and get verified. Withdraw funds IMMEDIATELY after they become available. 

My sincere condolences for your loss Michelle. On a practical matter concerning selling his system off, little could be added to the excellent advice given by Douglas Schroeder. He pretty much covered all the bases for you moving forward.

Go ahead and list the components and we may be able to suggest what you might expect to receive if you want to go to the minor chore of listing them or putting them up for auction... or let us know (generally/city) where you are and perhaps someone like Grannyring- who I know to be trustworthy- (as would anyone with lots of posts & great feedback) to be helpful in at least pointing you to an honest dealer. You can also pay a bit and utilize the "Audio Bluebook" function on this site. In general, you'll probably get about 50% of new value. You can lookup new prices by just Googling the equipment name/reviews. But consider this.....
As Tom6897 suggested, consider passing it along to his favorite relative/nephew who would appreciate it and always remember your husband/and you. Here's the advice I got from a quality gun dealer when I considered selling my (alzheimer's) father's very nice heirloom shotgun: 
He said, "One day your father will be gone, the shotgun will be gone, and the money will be gone." What a good dealer to convince me to keep it.