I'd go brushless but it really depends how much hassle you want between races and to some extent how much hassle you want between meetings.
I have the LRP Sphere speed controllers and there ace
As far as reliabilty for the motors goes, I have only had 1 problem. Basically the thread for the screws on the end bell came loose (I blame my dad for crashing it about 20 times in 1 lap though!!). Sent it back and it was replaced with a shiny new one.
From the option's you listed, your only going to spend and extra £50 to go brushless. For me, it wasnt a tough decision after I kept breaking brushed motors.
Ta
Stu