It is important to keep in mind, that if you operate abroad through a sole proprietorship, in most situations you can only make a contribution to an IRA or self employed retirement plan if the net taxable profit from your business exceeds your foreign earned income exclusion (if you are taking it). We can help you put together a US tax deductible retirement plan that will work for you.
Unless provided otherwise by a US tax treaty with the country in which you work (and there are only a few treaties that have favorable provisions) if a contribution is made to a foreign pension plan by your employer in your behalf, you must report that contribution as income on your US tax return and any earnings made on the funds in your foreign pension plan may also be immediately taxable to you. If you have a separate account in that foreign pension plan you may also be obligated to file Forms 3520 and 3520A each year to report information on that separate account which the IRS deems a foreign trust. Failure to file these two forms can result in extremely large penalties.