Honestly, if I had your starting girth I would have never gotten work done; that said, I've learned over the years that we all have our motivations and I'm not here to judge - it's just a matter of risk & reward.
Also, if you aren't in it for the long haul, I'm less tempted to recommend permanent fillers, especially for gain-goals of under 0.5 inches. Unless you happen to live near Tijuana, it's probably more sensible to travel to the closest qualified practitioner (see: Physician Directory
); There are always the inevitable minor-revision appointments; I can't imagine having to travel Internationally to touch-up 0.3 inches of girth with 2cc's of product.
Oh and I'm not against PMMA, it's still a viable & popular option, and I even have it inside of me. I'm just trying to offer you practical and sensible advice considering your situation.