The heel looks to me like a IOM TT rally guard that bike or motor cross riders wear as a heel protector during races, the boots certainly look like a lot of motor cross boots I've seen , the problem is finding one's that look the part , I would suggest going for white boots as this would be the easiest to dye or light tan or brown as alternatives Sidi boots have been mentioned before , use true leather dye not the dye you get from the shoemakers or shoe store , but what a tanner would use- most craft shops sell leather dye then you only need to fasten the shin guards using the buckles