Good horsemanship is about understanding horses and how to communicate with them. It goes beyond different types tack. That having been said however, certain types of equipment are easier to use and more effective than others. I like to use rope halters because they are narrower in diameter than web halters. This discourages the horse from leaning against pressure and makes the handlers cues much clearer. My favorite are those made by Double Diamond. They don't stretch, and I've found the proportions to be such that they fit the most variety of horses. When fitting a rope halter you must be careful that the cheekpiece of the halter is long enough. The noseband should sit well below the horse's cheekbone but above the soft part of the nostrils.
I have my leadrope tied directly to the halter- not connected by a clasp. A clasp will swing and bounce causing "signals" that don't actually mean anything. Thus causing the horse to ignore rather than pay attention to everything they feel coming from the leadrope.
I prefer leadropes 12 feet long and made from treeline ropes. 12 feet is long enough to get the horse moving out and around you, but short enough that you don't have a lot of excess rope to get tangled up in. One exception is smaller kids working with ponies. I will usually make 10 foot lead ropes for them. Treeline rope has a nice weight and feel. It allows the handler to send signals down the rope without having to make direct contact with the horse's face all the time.
If you're local to the Corvallis area, I know that Wilco in Tangent sells both the Double Diamond leadropes and the Buck Brannaman series treeline leadropes. They are also available on www.lostbuckaroo.com.