Really depends on what you are looking for. IMHO, Jasmine is prettier than Penny although they are both good looking woman. Jasmine has much fuller breasts. Penny is probably an "A" cup while Jasmine is more like a "B" cup. Neither are big breasted woman. Both have firm breasts.
Jasmine has perfected her technique and offers a fantastic release while Penny is not as technically inclined. (You really have to experience it to really appreciate Jasmine's technique!)
You will get much more mileage from Penny than you will from Jasmine. Jasmine is strictly an MP although she offers NR and Bodyslide. Penny has a more open menu which includes DATY and BLS. Some have suggested that she will do FS but only with repeat clientele.
Hope this helps you decide.