Agreed, capping them works fine. If you have some American size champagne bottles you can do it with regular 26 mm caps. If not, just get the 29 mm caps and the 29 mm bell and switch it out on your capper.
If you want corks you will have to get a corker. However, it does not have to be a champagne corker unless you want to use champagne corks. You can use plain wine corks and one of those cheap $5 plungers. Insert it all the way flush and then cap it. Or, I have been experimenting with inserting it partially and then caging it. Again using the cheapy plunger. It seems to work fine. You do not get the big mushroom, but it seems to seal well. Time will tell if it seals well enough to protect long term.
The simplest would be to get the plastic champagne stoppers and some cages. Not as classy looking but it works and you can stick them in by hand. I have even used those with Belgian style bottles. Te one caveat is that not all bottles work well and create a seal with those. You will have to test fit them. Ommegang bottles work well.
Speaking of Belgians, you can also cap champagne, as well as Belgian bottles, with the Belgian corks. These will give you the mushroom though not as dramatic as the champagne corks. They are wider than regular corks yet not as wide as the champagne. You will have to buy an appropriate corker, however one can be had for far less than the Champagne floor corkers. If you get one of the Colonna corker/cappers they are about $60. They work great for using the Belgian corks with a tiny bit of finagling. Plus it comes with a 26 and a 29 mm capper.