Hanging punching bag in garage

[Isocene]

I am trying to hang my punching bag from the ceiling in my garage. It's a water bag that weighs 120lb. Here is a picture of it hanging from a plant hook:
http://picasaweb.google.com/lh/photo/rBdTM2_R-bdwkr_rrd2Trg?authkey=Gv1sRgCN-ntq_82oyzuQE&feat=directlink

Here is the area directly above where it is hanging now:
http://picasaweb.google.com/maiku.pictures/PunchingBag?authkey=Gv1sRgCN-ntq_82oyzuQE#5337695939085439890

What is the best way for me to hang it?

I was thinking I could use this:
http://store.titleboxing.com/heavy-duty-wood-beam-hanger.html

In combination with:
http://store.titleboxing.com/hbs.html

And these:
http://store.titleboxing.com/shook.html

I guess to do that I need to cut a hole in the ceiling to put the hanger in, then put an S-hook/Spring/Spring Hook/Bag. Do I need to do anything to cover up the hole in the ceiling?

Other hanging accessories:
http://store.titleboxing.com/heavy-bags-heavy-bag-accessories.html

More pictures of the area:
http://picasaweb.google.com/maiku.pictures/PunchingBag?authkey=Gv1sRgCN-ntq_82oyzuQE#

I have no idea what I'm doing when it comes to these things and any advice would be much appreciated!

[searcher]

No matter how you decide to hang it, you need to re-inforce the area in your garage's crawl space by the truss'. If you don't you run a high risk of busting the truss. I have had this happen and it sucks to get fixed. Build it up with some 2x4s and make it more solid.

[jks9199]

Your best bet is really to find a good contractor that can help you assess where to hang it and how to support it properly. It shouldn't take a lot of their time, but you want to be sure you sister up and support it properly -- unless you are looking forward to having your ceiling end up on the floor.

[Isocene]

I didn't realize it would be that complicated! I'll get someone who knows what they're doing to do it for me.

Thanks for the advice