Rather than corking twist top bottles, see if your LHBS has the proper size twist caps for your bottles. Not only can you possibly break the bottles with corks, the corks will likely not fit the shape of the necks properly. Twist top bottles have an internally tapered neck. Bottles intended for corking have a straight neck and provide for greater cork contact area and thus a good seal. If you decide to go with corking twist top bottles you can use the shortest corks available and save a little money. Only a relatively narrow band of the corks will be contacting the neck of the bottle anyway. Synthetic corks would probably provide a better seal than natural corks.
I've used Corbel brandy bottles and then cut 1 3/4" synthetic corks in half. There was only about a 3/8" band of contact with the neck of the bottle but it worked. Probably not to be recommended for long term storage.
Rocket Socks Brewery