I have a professional vacuum sealer, which removes the air, and seals the bottle, or container.
Will this work with wine, or does the wine degrade once it has been exposed to air, no matter how well the vacuum sealer works?
The problem is the cork. One you pull it, you damage it. If you put a new cork of the correct size and "weight" for your bottle it will seal properly again and the wine will last many years
The small amount of air at the top of the bottle does not seriously affect the wine. A vacuum sealer will not remove that much air anyway (otherwise the cork would just get sucked in)
If you remove a sample of wine you should top it up with either distilled water, or wine from the same batch
Good vintage wineries offer services to open you r wine every 20 years or so, check them, top them up, and re-cork them. If done properly it will keep another 20 years!
Some wineries use carbon dioxide or nitrogen as an air replacement, but in history this was not done, and there are many records of wine lasting many decades
Screw caps cannot be easily replaced, you will need a screw capping machine, and I don't think they make domestic versions of these!
The only way to get "like it was never opened" is not to open it. But storing an opened wine bottle isn't a new question. There are a whole range of products, which will keep the wine varying lengths of time. From simple hand-vacuum pumps which can hold a day or two, to as-decanted nitrogen or argon replacement systems, which can add a week or two.
See http://www.wineenthusiast.com/serve-preserve/wine-preservation.asp?AfID=CJ for some product examples. The longest holding I've personally played with is something like http://www.wineenthusiast.com/nitrotap-single-bottle-wine-service-preservation-system.asp, which prevents oxygen ever getting into the bottle. However, even the bit of air between pulling the cork and inserting the spigot causes the wine to degrade within a week or two.
If you're looking to set up a bar, the nitrogen replacement systems can be found in multi-spigot configurations. So you can have 4 or 8 bottles "open" at a time.
As far as I know, it will still degrade a bit, but not that fast. Always keep in mind that "degrading" means oxidation which will kick in as soon as air gets into the bottle. So even if you remove the air after pouring, there was some air in the bottle, which means a tiny amount is oxidated.
To put that into practice: As long as you don't try to store the bottle for weeks, most people won't notice a difference. But still, the wine will change, depending on how good the bottle is sealed and how long it was left open.