hi Gary n Rob
Coming into this very late & have just noticed the date of your last post so you may well be advanced on this so will work backwards to what I planned to say.
Have you looked at the Clare Library website? It is gold for family historians with Clare ancestry: look at both the genealogy & history sections as well as photos.http://www.clarelibrary.ie/eolas/coclare/genealogy/genealog.htm
I had a quick look at the LDS (Mormon) library website: Feakle parish is microfilmed but only available from 1860. You mention you can't find McNamaras in the Cloonnagro townland. In my experience the Irish usually married within a close range of townlands and I see that one is on the boundary with Tulla so just maybe you might find the baptisms in the Tulla parish records which miraculously start in 1819, very early for Irish Catholic records. These are available through the LDS Church library near you.
I've been doing some work on migrants to Australia from East Clare (which I've defined as the Baronies of Upper and Lower Tulla). I don't have your McNamaras in my database as yet but am interested in what happened to East Clare people who came here. If you feel like it you could send me a private message and I'll give you my email there.
I'll include my shipping comments though you've probably already looked at them as you know the place of origin. (They appear in both Victorian immigration and NSW so may have slightly different info).
It might also be worth your while to have a look at the Immigration Deposit Journals which are indexed on CD (should be available in a major library near you). There will probably be lots of Patrick McNamaras but since you know where he was, if you find one who matches, you would be certainly interested in anyone he was sponsoring to come to Australia as they are likely to be neighbours, friends or family and again confirm linkages of people and places.
Persons on bounty ships to Sydney, Newcastle and Moreton Bay ('Board's Immigrant Lists'), 1848-91
reel 2461 (year 1850) ship range: Anglia-Tippoo Saib
Other immigration records (Agents Immigration LIsts) for Bussorah Merchant
Microfilm Reel 2136 NSW Archives Kit available in most libraries
According to another website the "Bussorah Merchant" sailed from Plymouth, England on the 3rd of February 1850 and arrived Geelong, Victoria on the 26th June 1850.
You might want to try Picture Australia for an image of the ship if you haven't already done so.
Anyway that's enough blather from me. You may well have passed this point of your research but since I started the post before I full checked dates I thought I may as well go ahead