Investing in first home with brother as a coborrower vs cosigner

[Erica Guide]

I live in the DC area which is very hot right now. I want to buy my first home. I'm 35. I have student loans of 11k, 25k saved, 100k in inheritance, a few interest free debt of about 4k. I make 65k a year but that is expected to rise in the next 6 months. 810 credit score. I have 2 dogs and will be spending a few grand in their care in the next couple of months. My brother is divorced, has a fiance who lives a state away and they have a baby. He doesn't expect to live with her until a year later because she is still in school. He has one child with his ex. I don't know how much he makes (I think the same as me) but he told me he has a credit score of 725. I know he has some debt but not sure how much. Currently we are living with and helping my mom with $1000k each a month. The house needs repairs. I want to invest the money I have into another property and rent it out the first year.

We saw a home come up in the area that is 440k for a sfh but it needs repairs. Since the market is hot houses sell within a few days and well above asking price. The house is a few minutes from my job as well. My brother first asked me to cosign with him but I think it would be better to be a coborrower since I want to profit from this property. I know that there should be some legal write ups when doing business with family and normally I wouldn't consider buying a house with family but I do want to invest the money I have and a dual income is needed for the market right now. The house was being rented and the area is hot so I think finding renters won't be difficult. My brother has a lender and a real estate guy he trusts and who had helped him buy a house prior. I have a few knowledgeable contractors. What should I be looking out for?