I assume you are referring to bamboo shoots as being the edible part, in that case, all are. However, giant varieties (growing over 3") are pretty much what is harvested. I'm not an expert, but all the giants I've seen are running not clumping. You'll be able to harvest clumping shoots, but the pain to harvest a .5-1.5" shoot versus a 2-3" shoot, may make it not worthwhile. You might also cross-post to the Asian forums.

Being a zone 7a, my thoughts concur with Ken. Clumpers are not normally harvested for eating, from what I can tell. I only have one clumper currently, having had many runners before. The shoots on the runners were MUCH larger than the shoots on the clumper.

You're not going to succeed in your climate zone with finding a clumper that has shoots worth bothering with for eating purposes. You would need either a runner, or a large clumper that grows in SE Asia, but not in your Zone 7.

Several clumping bamboos in the genus Fargesia are cold hardy to Zone 7a. Checking the list of Edible Bamboo Species reveals that Fargesia robusta is considered "edible", although it falls short of the better categories "good" and "delicious".

Yes, fargesias are very cold hardy, but the shoots are about the size of a green bean. So, apart from the fact that the shoots are simply “edible,” the size means they aren’t really worth bothering with to harvest.