Which motor and ESC combo for CAT SX3 Pro

[Cougar]

I have got myself the Cat SX3 Pro. Not got around to building it yet as I am working abroad. I am trying to decide on a motor and ESC. I was thinking of getting the HPI Flux Pro Comp motor, either 7.5T or 8.5T with the HPI Flux Pro Comp ESC. Have any of you had any experience with these?? I also noticed that a lot of people run SP combos. I also thought about the SP GT.2 Pro ESC with the V3 Pro Comp motor, again either 7.5T or 8.5T.
Batteries I am going with Orion Pro Carbon 5500mAh 90C. As for the servo I am stuck between 2, the Alturn USA, 15.2kg, 0.09sec or Savox of some kind. Any suggestions??
Unfortunately, I do not race on a proper track as there are none near me, but me and my mates set up our own track in an old quarry which is quite good.