What you will need is a Self-directed IRA, after you set on up you will be able to request a direct rollover from your 401k into your newly established SD IRA.

If they are you should consider establishing an LLC & taking advantage of Illinois Land Trusts for your current portfolio & future purchases. 

I think it both saved them money and helped them establish some ownership of the house.

If you are lending 100% of the after repaired value, as @Ellis San Jose says, that would be foolish.And for me, I would be reluctant to loan 100% of purchase + rehab costs until I had a more established relationship with the borrower.

Establish value - Do this through a BPO, get the comparable sales data for that property, pictures, opinion of value. 2.

Establish your financial goals, and be specific.

The cash receipts of the Company shall be applied in the following order of priority: (1) To pay the debts and expenses of the Limited Liability as they become due; (2) To the Asset Manager of the Limited Liability Company his fees as described herein; then (3) The establishment of a necessary reserve of funds as determined by the Managers in their sole discretion; then (4) To the Members of the Limited Liability for their preferred return as described herein; (5) To the Members in proportion to their membership interest; and Section 4.03 Preferred Returns.

Best to partner with an established person that you already know who is active in the USA.

For 1031 there is the establishment of intent - not a specific time period. 

It will be capitol intensive to develop and would probably be best for established developers.