You're alot braver than most.. 8O
As far as the RP-x, I would recommend against it. Any med that requires the removal of any animal for any reason is not a good choice. If you get a chance to see a bottle, you will be very suprised to find out how many animal types cannot be kept in the tank with it's treatment.
The Probiotic Marine Formula is still what you might call an "unkown" as there seems to be little literature about it. From what I have heard it is much better as a preventative than an actual cure. If you do use it as an actual treatment on an infected fish, please post the results or submit a >>review
<< of the product.
I wish you all the success but you already know what I would otherwise suggest...