The one piece of specialized equipment that éclairs require is a pastry bag and tips. Now, I’ve used many types of pastry bags over the years, from cheapie little paper doo-dads to elaborately-stitched European wunderbags. The conclusion I’ve come to: nothing beats a Ziploc for its combination of versatility and price. Just clip one of the lower corners, screw on a pastry tip, and you’re ready to go. When you’re done, detach the tip and pitch the whole mess out. Easy.
Just make sure you get the heavier freezer variety, preferrably with the double-zipper thingy. Having emerged from the kitchen more than once with a face-full of raspberry jam, I can tell you the extra protection is worth it.
(NOTE: To prevent filling explosions, don’t overload the bag, and press any air bubbles out of the bag before you begin filling and/or icing.)