I have about $100M in IRAs that I would like to invest in real estate.
 I also have money in 401Ks.

My father has a house, a barn & 15 acres in Vermont & the prices have been
increasing.  He is 75 & wants to move to small place in Florida during
the winter & he needs maybe $100-200M to buy this place in Florida.  I
want to buy his barn & 5-10 acres of his property for investment.  I
do not plan to buy his house & the other five acres.  I plan to
renovate the barn (plumbing, electrical, fireplace, kitchen, rooms,
etc)  so that it can be rented.  I believe that it will make a return.
 I want more investments in real estate.  I will spend money to fix up
the barn and then I will rent it for summer, fall colors, ski season,
etc.  I want to buy the property at market value (no discount for
family etc).  Can I use my IRA funds to pay significant down payment
etc??  I understand that
real estate IRA investments have restrictions regarding family. 
Again, I want to prove that I am buying at market value.

Any advice on how to accomplish this?