Have you already purchased your electric fence? If not, I HIGHLY recommend this rope: http://www.premier1supplies.com/detail.php?prod_id=17857&cat_id=41
I've used different tapes and have had friends use the actual wire (which you've already said you're not using) and this stuff is tons better. The tape knots/kinks easily and sags or twists. This rope is highly visible, soft, easy to use , looks nice, and is durable. I've had it out in my fields for probably close to 10 years now.
laissez faire, laissez aller, laissez passer, et laissez les bon temps roulez toute la nuit! www.phyxiusphotos.com
Christina Dale Equine Photography