I have a Tropic White and an Indian White Guava. Mine are not as big as yours and have been in the ground a year. My two are planted in a western exposure so they get lots of sun. However last summer and this summer I have shade cloth on the west side of these to help get them off to a good start. As soon as they are bushier, possibly next year, the cloth will not be put up. I was told that they can take the heat so we'll see.
One possible extra benefit of planting guavas is that they have been doing research with inter-planting guavas with citrus to control citrus greening disease. So far the research has been promising.
There is a tropical fruit forum on Garden Web that may help you if you don't get any more responses here.

Where did you pick 'em up?

Nevermind, saw your other post.