The Haak Vineyard over in Santa Fe tried growing olives a couple years ago but I don't think they had any succuess. You could try calling them up to see what varieties they planted.

I dont think olives are a good bet in Houston.
Olives like a little less humidity than what houston has to offer in the summer, and to produce fruit they need cooler nights than what you get in Houston. You could still gro as an ornamental, keeping an eye out for scale pests and fungal problems,they like excellent drainage too.

Olives are amazingly easy to grow even in Houston. I planted a small one in the ground last fall, and it is about 26" tall already. Check out Sandy Oaks Olive Orchard located near Elmendorf, southeast of San Antonio. I think that you will be happy to find out all the important information on growing olives!

There is a bed & breakfast on the island called the Olive Tree that has olive trees in front that are over 100 years old. They and others on the island produce olives.
Taly HO!

I have 2 tree's that I planted over 2 years ago, and are now 6' tall in Spring. I bought them at Fanick's garden center in San Antonio, the folks there said they are the same vareity that are used in the olive groves between S.A., and Corpus! Haven't put fruit on them yet, but are very healthy looking. ( I believe these are a Spanish var. that originated in Seville Spain)
Jer