I have two data sets: one for "good old customers" and a newer one with "new customers". My need is to "predict" which ones of the new customers would be rated as "potentially good customers" using the good customers data and variables.

So, a simple train & predict problem. My issue is I only have one-class-target.

Searching for one-class classification in R reached this Stack Overflow answer One-class classification with SVM in R

Pretty useful but I need any other method instead SVM: randomForest, ctree, gbm....

Does any other than svm allow one class classification? anyone has any example using another R package?

Asked same issue on SO, but someone recommended me to post here due to lack of answers there.