Buying unfinshed project from Investor

[W. Alex Benitez]

Hello fellow BP members....

In driving around this weekend I found a multi-family property which is being rehabbed.  I called the number listed on the lawn sign and met with the investor.  He guided me through the property which is 80% and still needs the kitchen, front deck and some other items.  

I would like to make an offer on this before he lists it with his agent.  However, without the project being completed, what would the appropriate "next steps" be?  I plan to contact him and see if he has a list of materials (cabinets, appliances, counter tops, etc..) he plans to use for the remainder of the project.  In doing so, it would allow me to gauge what to estimate in my offer.

Tips and comments appreciated....

PS...are there any clauses I can add to my contract to "CMA" such as making sure he pays his contractors so they do place a mechanics lien on property?