If you have a good headset, or maybe a small speakerphone, you can most likely attend Adobe Connect meetings using your existing computer and internet connection.
You only need a fast computer/laptop, which is not more than 3-4 years old, and an internet connection at 1 Mbit/s download and 256 kbit/s upload mininum. Less can do it, but then you need to configure Adobe Connect correctly.
We advise you to use a USB headset for better audio quality and configuration, but for better convenience you can also use a small speakerphone - for example ClearOne Chat 50.
Logitech Webcam Pro 5000 > built-in web camera in existing laptop/monitor, other USB web cameras. Be aware that only few USB web cameras support the Mac plaform.