Inner,
YOu dont need to do the FAA PPL, you can jump straight in at CPL.
You can also combine the courses, i.e I did my ME / CPL / IR (already held a IR(SE)) together in the Seneca 2 and did one checkflight for issue of both licences. I then did the SE CPL later on.
IR SE(if you hold a JAA IR) will prob take you about 15hrs at about $120/hr
IR(ME) is a couple of approaches inc. asymetric to add the ME to your licence if you already have the IR(SE).
CPL about 10-15 hours at about $120/hr
ME I think is 5 hours although I did the ME and CPL training together and also required 25hrs dual for solo hire so worked out quite nicely. Think that was about $160/hr.
Checkflight was about $350 plus cost of aircraft, say 1.5-2 hrs.
Dont forget your writtens, long time since I did one but think they ran about $50 each.
Hope this helps a bit!
J.