how does one pick an oracle deck to use

i have been told that since i am such a geometrically oriented person ; because of my welding, machining and woodworking abilities; that i might try using the "scared geometry oracle" deck for insight as opposed to something like the "celtic tree oracle" deck...

since no one really know when tarot decks came about, could oracle decks go back further than the tarot??

are magik decks the same as oracle decks??? like Lo Scarabeo's magik card deck???

Were they referring to the one by Francene Hart or the one by John Michael Greer?

I have the one by John Michael Greer: Sacred Geometry Oracle
Llewellyn, ISBN: 0-7387-0051-7
http://www.learntarot.com/sgdesc.htm shows scans.

I haven't had time to go through things the way I'd like, but I have most of Greer's titles on geomancy and like his writing/teaching style. The companion book gives upright meanings, reversed meanings, an exercise, and a meditation for each card.

ETA: I choose oracles (and tarot) based on what I'd like to learn more about. When I find a subject matter that clicks, I get as many decks of that sort as I can find.

yes, the one that you link me too is the one i am talking about.... it seems to have some type of extreme meaning to me based on the shapes and figures that i have seen on the cards themselves... i guess based on that that is probably what is should get since they seems to jump out at me over any of the others that i have looked at