Different adoption situation. Where to start?

Hello and thank you for reading my post. Here is our situation. A close friend of the family (since my husband was 2 years old) has a brother. Now her brother "Bob" is 70 years old his wife,"Meg", is very sick with a terminal illness she had a 15 yr. life expectancy 20 yrs. ago and she is starting to decline. Meg is the bio grandmother of a 9 yr. old boy "Tim". Both Bob and Meg have raised Tim from almost birth. Tim's bio mom and dad have moved on with their lives and they gave custody to Meg. Now Bob and Meg are on every government support help you can think of from housing, food, medical the whole bit. The fear is that once Meg (bio grams) dies Bob (not bio grandpa) will lose custody because of being on programs and he is not in a position to care for Tim himself with out Meg. My family is willing to adopt Tim so he can continue being a part of the family he know, be in a good home and not enter the foster system. My husband and I are 26 and 29. We have two little boys 2 yrs. and 4 months. We own our own business and have close ties to the community and church. How do we start the process? Bob and Meg do have a social worker do we all talk to them? Would my family even qualify? I read someplace that you have to be 30 to adopt. Is this true? Do we even need to adopt? Our will states our own boys go to my husband's parents upon our deaths. Could Meg do the same thing naming us caretakers after her death? Thank you all again for your help and God bless.