Most construction businesses of what you are trying to do are probably very-busy, and lead time is out-there, probably months. For such a small job, you might be best-off trying to get them to give you a 'leftover' load, after they have done a bigger job. Yours is really 'small-potatoes' for them. I expect a pump/hose would be the easiest way to go. You might try to see if the concrete truck has someone who can pump their load for you, after a bigger job.
Since you have some bikes worth saving, you want to have the job done properly. The climate control for the building will be important for vehicle preservation, but that's all a guess, since you don't have what hemisphere you're in under the avatar.