Going in for the surgery while still relatively strong made sense to me. When I was 40, in reasonably good health, with a good job and good insurance, I asked my doctors 'how sick to I have to be?(to get the valve replaced)' Their answer was 'let's do it now.' I haven't ever regretted asking that question or making that decision. (FWIW -- less than a year later, I no longer had the job or insurance, but I DID have a St.Jude's valve clicking away in my chest. If I had waited, who knows what would have happened?)
I really recommend - to you and others taking warfarin - that you get a meter (you said that you were pricing some) and test weekly. Also - based on a reputation for returning INRs that are higher than blood draws (and there's a thread here that gives a formula for converting InRatio results to lab results), I personally would not recommend an InRatio meter (although I now have two of them). OTOH -- an InRatio meter would probably be okay if you're aware that the results are usually higher than the lab results (once I learned of this consistent error, I've subtracted .3 - .6 from the InRatio results and was able to get a pretty strong sense that my INR was in or out of range).
Good luck with your surgery - although you won't need it - choosing a good surgeon, with a good surgical team, at a good hospital should be all the 'luck' you should actually need.