I live in a large city so, check the phone book for medical supply stores and large drugstores. You might then try calling to ask what equipment they have available. However, you might find that you just get excitement going to check out what's available at drug stores.
When, about 10 years ago, I found out about colon tubes, I started to call around and ask if they had them for sale. Several of the places said that they could only sell one with a Dr.s prescription but one, Horton and Converse, said that their branch didn't carry them but to call one of their other ones and ask for a certain individual.
I went in to this pharmacy and, of course, enjoyed looking around for awhile. Then I asked for Jack and he began showing me the two sizes of colon tubes he had in stock. (He may have been into enemas as well, because he seemed excited by the questions and comments as well.) When he showed me the colon tubes he said, "It's OK, you can touch it."
After deciding on a colon tube I asked him how it should be connected. He said to just connect it to the bottom of the bag--which was an open-top fountain syringe in yellow rubber. My response was that the length wouldn't be sufficient. He then had an Aha moment and took me over to the ostomy section and found a clear plastic tube with a fitting on the end. It was about 5 feet long and worked perfectly--for only a few bucks.
What I'm suggesting is two-fold. First, have some fun looking around, and second, improvise. Part of the excitement of enemas is the preparation. Go for it!