Having a penectomy would condemn you to having sigmoid colon type SRS from which the results are, let us say, variable. The surgery is much more complex, when done there can be ongoing problems with discharge and odour, and the cosmetics can be poor.
Besides which as a doctor (which exams permitting I will be next year) I would almost certainly require exactly the same level of qualification for a penectomy as I would for SRS - so if you could convince a surgeon to do one, then by definition the same surgeon would be willing to do SRS. Nor is the cost going to be much different - so to put it rather bluntly this is a completely pointless and non feasible step, which would convey no benefit in timescale cost or eligibility to you.