You definitely need the help! I would, in making the decision, sit down and write out the pro's and con's on each. If there is any issue of mistrust, I would definitely rule those out. Probably most care-givers that have hired help have lost some things - great-aunt's jewelry etc. But I do remember one gal that we hired through hospice (talk about some issues) actually ended up literally saving my Dad's life. We remain friends to this day and some of those issues are still with her - ah well... Her heart is in the right place!
The reason that I suggested Faith in Action is because it is a volunteer organization. I have heard that there may be opportunities for respite through some organizations which it sounds like you and your DH need. I know that is a big concern for you. Do you have any other siblings besides the brother you have mentioned? I wasn't married when I cared for my father and TG for that. That is another huge stress that I cannot imagine trying to deal with...
I am sorry that I am the only one that has answered. I have been posting on this site for near ten years and have never seen it so slow. It must be a cosmic thing - I don't know. It's not like care giving has gotten any easier or is less demand. I think that perhaps people are afraid to talk about it because it is such a sad thing mostly. It takes guts to reach out... Doing so, however, I believe makes us stronger. There is empowerment in releasing to the universe!
Hopefully, there is some help in my response. You certainly need to have the help so I would definitely look at two things when making a decision - trust and attitude. I think that you need someone that is honest and caring if that helps.
Just remember to be gentle with yourself! Take some time and explore your thoughts and feelings - it is okay and even natural to feel some anger, but for God's sake please don't percolate in it like I did! Wave it away... In the meantime, trust the universe!