OK, here are the answers to your questions:

Type of diving - Recreational
I intend to continue recreational diving for now. As far as long term, I am not sure where diving is going to take me, but IF I do get into some more serious wreck diving or technical diving I know new equipment will be needed so my purchase is for what I do now. If I get into teaching or become a DM, then I will probablly use whatever the shop sells as they usually like that.

90% of my diving is done at Willow Springs which has a max depth of 55 ffw, BUT I have never found that deep spot yet, so most of the dives are in the 40 ffw area. I do go to other places of course, and one of the reasons for my purchase is a pony bottle requirement for ocean dives in the Atlantic. I would like to take a few wreck dives this summer and either need to own or rent one. The other reason for my purchase is obvius, to have a redundant air supply whenever I dive. I went with the 19 cf because it was an a nice size/weight/air ratio. I know the Spare Air is pretty much useless for my needs as it is only available in a 1.7 cf and a 3 cf.

Oh yea' I don't do any type of decompression diving at this time, no overhead environments, no serious wreck penetration, etc. If I ever do get into more advanced diving, I will go to doubles and such.

All that being said, my question still is do I need and am I required to have a octo. on my main regulator when I have a pony bottle regardless any type or size?

And about the thread with the Aunt, I never doubted the fact that she had a problem with her regulator, I had issues with the rest of the "story".