Today's Japanese toestraps are much better than anything the Italians or French ever made 30 years ago. They have a plastic laminate that makes them almost unbreakable, and the buckles are stronger metal and fastened on the better ones with two solid rivets instead of one. They last forever and a day.
Choice of a double vs. one or two singles depends mostly on the pedals you're riding and your particular foot shape and pedaling style. Some riders can cross two singles across each other to avoid painful pressure on the top of the foot.
If you like to use PD-7700 SPD-R pedals instead of traditional slotted-cleat ones, you have a dynamite system to which you can add a toe strap (or two, if you really feel the need). Theo Bos and many of the top worlds sprinters use a single strap these days in conjunction with PD-7700s. The pedal/cleat connection takes a lot of the stress off the strap and lets you have a little float, which slotted cleats just don't give you. Check
www.businesscycles.com or
www.bensbike.com for the best selections of toe straps. Bensbike sells a lot at slightly lower prices on eBay.