Almost all of us have run into this issue, including myself.
We have so many ideas, so many visions, and so many images bouncing around in our head, yet we do not have the equipment or resources to achieve the photograph we desire. It's very frustrating, is it not? A thought comes in to your head... well it would be cool if I could do this, or have a photo portraying that. But then reality sets in that maybe you don't have the right lighting equipment, the proper lens, or the amount of models wiling to sign a model release to create the image you would like.
So what do you do? Well one thing that we should not do is give up on those thoughts. Do not push away the crazy, creative ideas that pop into our heads when we're watching tv or day dreaming at work.
One thing we can do is write those ideas down. Write them down in a notebook, journal, or just a scrap of paper... and who knows? Maybe those thoughts will be useful down the line? While I am still not nearly as successful in stock as many others out there, when I started out I had very little equipment and money. But I wrote down those ideas I had floating around in my head, and now I am just beginning to revisit them.
And now that I've been able to invest more money into my photography from my stock work (and an increase in hours at my day job) looking at the old ideas I wrote down in my notebook have inspired me to try to create those images I couldn't have created before. Whether its getting an upgrade in photoshop, or buying an extra soft box, anything that adds to my equipment is another chance to try and revisit an old idea.
So don't give up on those ideas spinning in your head. Write them down and later revisit them. Perhaps you'll be able to use something, perhaps not. But there's nothing like exploring your past to see how much you have grown into the present.