Hi Luis, welcome to the forum! I am not super familiar with plums, but I do know there are a few natives that grow more like shrubs you might want to check out, I think sand plums is a variety I’ve seen discussed.
Here is a currently active thread for various cultivars and some of their traits, however size is not one of them. Plum crack hose - #34 by alan
I imagine if you picked one with low vigor (read:grows slowly) you would be able to keep it pruned to a manageable size in perpetuity.