+1 on the EZ Cap bottles. Man those things rock. Well worth the investment.
I use OneStep as a sanitizer and you do have to be careful when sanitizing the swings and caps (the metal parts will oxidize and weaken over time) but I devised a good method. I take a shallow glass pie dish, arrange the swing cap mechanisms around the rim so that ONLY the caps and gaskets are sitting flat on the bottom, the rest of the swing hangs off the outside. Then I fill the dish slowly with sanitizer until the level comes to just above the gaskets before any of the metal.
I just picked up 50 of them on Craig's List for $4 (I love Craig's List). They are a LOT faster and easier to bottle with than capped bottles. The only thing I've found with swing top bottles is that the gasket should be removed when the bottles are cleaned. Otherwise there are lots of crevices for non beer friendly stuff to accumulate.
A nice thing about Grolsch bottles is that they use stainless steel for the bails instead of galvanized.
I was able to purchase 15 or so Grolsch style bottles off of craigslist. The great thing was they were brown glass and not green. They were from some German beer company from what the guy I bought them from told me. I love them and wish I had more.