I have Hi Spec front brakes and have not had any issues with them. They are fitted to the RS Performance Levante so they obviously think they are OK stopping a V8 powered car. I have non vented standard Caterham disks as I wanted to keep the unsprung weight down, what with a 2.5KG weight saving for each caliper, compared to the cast iron originals, this helps the suspension move more freely.
You are just down the road from Hi Spec and if you deal over the counter with them you should be fine. If you want to spend double the money then buy the Caterham ones, or alternatively talk to Rallydesign down near Faversham about Wilwoods, which also seem good value.
Nick
Lava Orange Caterham Blackbird