Wrap Around Question

[Allison Slaughter]

My boyfriend and I are moving - currently we live in a fixer upper he purchased a year ago. We have done a lot of work on it but it still needs a ton more done before it is ready to be rented out. He is in the process of finalizing his mortgage on the new house. I am not on either mortgage. The fixer upper that we live in now, I want to purchase and finish the renovations and then use it as a rental property. We have run the numbers and it works as a rental - the rental market is extremely hot here. It still needs about $20,000 in repairs. 

How would you suggest doing the financing on this? I have the cash to do the repairs OR the cash for a 20% down payment but not both. If I go and get traditional financing I know they would require 10-20% down since it is an investment property and we won't be living here.
Open to all ideas and suggestions on how to make this work. We have talked about me going to get a loan and seeing if a smaller bank would give me a renovation loan and then refinancing out of it once I have a tenant in place - ARV is conservatively $140,000 and purchase price would be $90,000.

I have also looked at doing a wrap around mortgage - he has already been approved for the new mortgage even with the existing one in place so we are not worried about that. I have looked up wrap around mortgages but having a hard time figuring out exactly how that would work as far as insurance, taxes, etc. 

My boyfriend has also offered to just let me pay the mortgage until I can get the renovation done and then to purchase it since it would appraise higher so I would have 20% equity in the house at that point, but it would be nice for him to have a little extra cash right now for closing and stuff on the new house.

Open to any and all ideas... this will be first my property and I plan to BRRRR it.