To begin with, it's important to check each of the devices you'll be travelling with to determine whether they're designed to operate from 100-240 VAC. That's likely the case with all the devices you mentioned, however it's still a good idea to check. Look for the words "Input Voltage" on the nameplate of each device.
You don't need a Voltage Convertor and in fact it would not be a good idea to use one. What you will need is Plug Adaptors to adapt the North American plugs to the European sockets. If you're only going to be in Paris, you'll need the 2-pin Euro Plug Adaptors with two round pins. I'd suggest packing along several, as they're easy to misplace. The model shown in the link is a bit pricey, but you can usually find them cheaper at Wal Mart, Best Buy or other stores.
Using a Power Bar is one solution to charging multiple devices, but you MUST ensure that the power bar does NOT have surge suppression, RFI filtering or similar frills, as it will likely self destruct as soon as it's connected in Europe. A basic model with no extra frills is best.