I have had nice results w/ the Medtronics pump and CGM. The results seem to correlate nicely to me meter, most of the time, and having the CGM and pump in one unit is useful for running. I had one fail after a 14 mile run, in 87 degree heat. I never bothered asking what blew up on it but I had a new one the next business day. The other pump brand(s?) don't have a CGM. I don't mind lugging stuff along (pump, meter, sugar, gatorade, sometimes iPod...) but the Dexcom has another unit you have to use to get the data out of and to use for a meter. I know there are units that will hold it so it's not a deal-breaker but the Medtronics seems a bit more compact.
I just got a 523 model pump (warranty replacement) and it says it's ok up to 104 degrees? I had one fail last summer on a *really* humid day that started out 87 degrees at 6:30 AM and was in the low 90s by the time I was done? I dunno if that was connected to the heat or not?
I think medtronic minimed would be great for you, If you are getting the CGM its all in one system, I am a runner (I don't have CGM) and I use the Minimed 723 model.