I'm with Andreww on this one. Any modern 7750-based rep (6-9-12) should be as good as you need. It's not going to die in 35 minutes and as long as the chrono second hand is well built, it'll work perfectly as a chrono.
I tend to believe that it doesn't need servicing out of the box as I have several one year old Asian 7750 replicas that are running as well as when they were bought. The Zigmeister, upon servicing my GST, said the movement was pristine. Sure, a service is worthwhile if you can afford it, but if you buy replicas with the intention of getting one to two years of life out of them, it's not needed.
Watches like the Aquaracer, Aquatimer, Carrera, BCE, GST, etc., will all be fine. Even the HBB with the added layer to move the 12 to the 3 will be fine as that's exactly what the gen has instead of the 7753.