If you want a road bike and carbon fiber at that check out the Orbea Orca (you will have to buy used). I have been riding mine since I was 396 pounds in 2015 (am now down to 360 pounds). I bought my 2013 model brand new in Jan 2015 for $1700.00, but I would think you should be able to get one of that vintage for under $1000.00 now.
You will probably need to upgrade the wheelset, but the 32 spoke wheels it came with served me well for a year before needing to replace them.
Good luck in your search.