We are not US tax experts, but as we understand the law, you can form a “self directed IRA” using your existing funds. The overseas investment cannot be for your personal use. Your IRA funds can be co-mingled with additional funds if necessary

“A self-directed IRA is a type of individual retirement account or IRA thatallows the account owner to include hand-chosen assets or investments in his own retirement portfolio. The term “self-directed” has no legal connotation, but is merely an industry term which indicates that the IRA owner has been given greater control by the IRA custodian or trustee over the investments within his own portfolio.” (* Nu-Wire Investment Wiki Pages)

With the use of a Honduran corporation, part of your portfolio stock can be purchased with funds from an IRA or IRA/SEP and part from non IRA type funds, allowing you to live part time in your purchase if you were to choose a condo or home and part time your IRA would generate rental income from such.

Here are some links that can give you more information about this:
http://www.nuwireinvestor.com/articles/diversification-through-self-directed-iras-51210.aspx
http://newdirectionira.com/
http://www.nafep.com/ICO/self_directed_ira.htm
http://www.freeselfdirectedira.org/self-directed-IRA

The below IRS link may also be of help reference-
http://www.irs.gov/businesses/small/international/article/0,,id=97130,00.htm
Following is the contact information for a company we have seen do this many times: The EnTrust Group
www.entrustgroup.com
(800) 392-9653.
Here is a link to an interesting article:
www.nuwireinvestor.com/article.aspx?id=210