What is the biggest hoop a 350E will take? Will that hoop take up any more room to move the arm holding the hoop? Another words how much more room will I need to have for the arm to extend to the back? How much more room will I have to have to have the arm move to the side? for the hoop?

The largest hoop is the 5X7 hoop. Yes, you can use the gigahoop but you will learn later exactly how to use that.

The can only extend as far as the 5X7 hoop.

If you can find one, I do suggest getting a SEW STEADY table sometime. This will help support the hoop and prevent it from getting "bumped" while embroiderying.

biggest hoop is 5x7

Think I understand what you are asking .The biggest hoop is 12 1/2 inches long . I haven't used this one so not sure exactly how far back it goes... Probably have to have at least 10 inches clearance ,out to the side probably 3 inches. That is one of the reasons I purchased the Janome instead of the brother because the brother was so much bigger and needed more room.
Hope I have understood your question.

This isn't exactly what you asked for but just FYI--
Go to--
http://content.janome.com/index.cfm/...roidery/MC350E
1. Click on Accesories
2. Click on Categories
3. Select hoops
4. You can then click on each hoop listed for a photo and it's size

Thank you for the information. If you ever hear of anyone who tried this on a janome 350E, would you have them let me know how it worked?

Thank you for the information.

My husband is building me a sewing cabinet, big enough that I can also use it for quilting and a cutting table. So, I should have enough support for the hoop.

I notice where you lived. My son in law and daughter was stationed at Fort Leonard Wood about 10 years ago, and we were in your town a few times. If I remember right, we even bought a car there to tow behind the motorhome. It seemed like a nice town. I also like Missouri, it somewhat reminded me of home. The people were very friendly.

Thank you again.