There are a number of threads on this site which address the issue of titles and the Crankshaft Coalition has a wiki devoted to it http://crankshaftcoalition.com/wiki/How_to_title_a_hot_rod
There is also some good discussion of it over on the H.A.M.B. http://www.jalopyjournal.com/forum/
(once there just enter "titles" or similar search terms to find the discussions).
There are three "legal" ways I can think of to title your rod. One, if you can find an original VIN stamped on your frame you can use that to apply for a lost/replacement title. Second, you can go through your local DMV process for titling a street rod. Or third, you can use on of the "bonded title" services which can be found on the web. Note, however, that bonded titles are not accepted in some states (I don't know about Iowa but the bonding company can tell you immediately if they are acceptable in your state).
You should be aware that using a "dead" title, such as those you by on the internet, is NOT legal and if caught, you can be charged with fraud. That's not to say this option is not used...and used quite a bit...by rodders in similar situations to yours. Just be aware that if you want to be on the up and up, it is not the option you want to take.
And regarding your question, you should be able to find a '29 tudor title (sold for "collectors" purpose only) in the neighborhood of $150-$175. While it is true that '32 titles are becoming difficult to find, the years prior and after '32 are still pretty widely available. There are guys on the HAMB (see link above) that can direct you to some additional sources.