CORKS:
Not much to say here except that you should get the best quality corks available, especially if you want to age your wines for an extended period of time.
All corks, except plastic, are gas permeable which plays a part in the ageing process. Poor quality corks may allow an excessive amount of air to come in contact with the wine. This will decrease the shelf life of the wine. Poor quality corks are also more prone to leakage.
If you are using the standard 750 ml. size botle, you will need aprox. 25 bottles for a 5 gal. batch.
CORKERS:
As with beer bottle cappers, wine bottle corkers come in hand held and free standing styles. I have never used the hand held corkers, but they are less expensive. I use a free standing model which I used to rent from my local homebrew shop. Now I have my own corker, but renting can be more economical if your volume is low or you are just starting.