Hi, as far as I know, SPSS can’t do PSA (I believe you think about Propensity Score Matching for estimating “causal” effects). However, I quit SPSS at version 15, so perhaps something changed.
Stata has excellent user-written commands for matching, especially -psmatch2- and also -pscore-.
There are a few different ways to do the matching for propensity estimation – and most of these SPSS is capable of, you just need to do a little more work by hand. E.g. you can use logistic regression, and then use predicted probabilities to calculate the weights.
However, I use R, as it has a boosted regression based method which seems to do a better job. The program is called twang, and it (along with R) is free.