Although some are a more relaxed about it now, many doctors are reluctant to become involved in the touchy subject of testosterone replacement, so you could have difficulty finding one to prescribe for a PC patient. It's a risk / reward judgement.
You could consult a specialist in ED if you havn't already done so.
Two people have indicated to me that they had an implant, with no problems and good results, although I don't know what the overall success rate is for implants.