Any chance you could give a hint as the best place to buy the hand grips , anchors, or the "hardware" for such a wall??
I am aware of Google, but I was curious cause you had SO MANY...
Thanks,
-T
The holds generally come with the one bolt and one t-nut. You only need 1 bolt per hold obviously but you need a heck of a lot of t-nuts to make the wall modular. At first, I bought a few of the extra t-nuts at the climbing supply sites or big box stores but they were incredibly expensive. So, I went to Fastenal and they were like 1/5th the price or even less--I can't remember now.
Here's the fastenal link:
http://www.fastenal.com/web/products.ex?N=999600087
The holds I found from local stores and online supplies. Here's one of the cheaper ones:
http://www.cheapholds.com/holds.shtml
Here's one of the better companies in the industry with high quality holds:
http://www.metoliusclimbing.com/climbing-gear.html
Here's a guide to building your own wall:
http://www.metoliusclimbing.com/pdf/How-to-Build-a-Home-Bouldering-Wall.pdf
My recommendation on the holds is to try to find local suppliers (secondhand or whatever). If you are going to buy new, order the large kits--the bigger the better. You get a better discount, sort of like large toolkits. My holds are a mix of whatever I could find on sale. You can contact local climbing gyms and see if they are getting rid of any holds. They hold up to a lot of use and you can clearly see if they are cracked or damaged.
Don't feel like you have to buy all the holds at one time. You can always add more as you find a set on sale. But, make sure you drill more holes than you think you need and put the t-nuts in them. Once the panels are flush with the wall, you can't get behind it anymore to add new ones.
For the padding, I just used an old mattress. If you are going to do something a little more permanent, like in a barn like rieferman mentioned, I'd get a bunch of old tires and have them put through a shredder and lay it about 6-8" thick at the base of all the walls and under any overhangs. Many of the climbing gyms have that sort of padding.
I would keep the wall up if I had more room. It's really awesome for the kids to play on and they can do it all year round. It's just that I have a 2 1/2 car garage and I need the space for storage and working on stuff so the kids get bumped out of this space

They've bumped me out of the rest of the house it seems like, so I don't feel bad about this and their interest has waned over the years. But the rest of the kids in the neighborhood think it is the coolest thing they've ever seen.