Don't use your homeowner's policy, you risk a premium increase if you have a claim. And, if you have ever made a nickle from anyone through photography, they can deny your claim...
I too have a Personal Articles Rider on my State Farm homeowners which costs me $162 for $10k in coverage. This coverage includes lost or stolen equipment even while overseas. I actually need to update mine as well with the addition of a 7D and a couple new lens.
While I can't speak to other homeowners policies, claims against my personal articles policy does not affect my homeowners rates. If State Farm were to ever deem the claims to be excessive, they simply dropped the personal articles policies. Your mileage may very.
It's important to understand that most 'standard' homeowners policies include photo equipment, they are completely inadequate for anything beyond a basic Rebel kit.
The professional policy suggested as an alternative is many times more expensive and also appears to be a full blown professional liability policy designed to insure a photography business as opposed to just photo equipment. These are apples and oranges we are talking about.
For those of us who are amateurs with a lot of expensive equipment who only very occasionally sell a photo, a personal articles rider is most likely the most cost effective way to insure our equipment. And no, the fact that you once sold a photo does not preclude you from have protection under a homeowners or renters rider. If in doubt, as your insurance agent. You can rely on his or her advice as they are legal agents of the insurance company.
If your photography "hobby" requires an IRS Schedule C every year, you need a professional policy.
When looking at equipment policies pay attention to the fine print and make sure the policy you buy is "primary" coverage as opposed to "secondary". Secondary policies (like the ones they sell you at the rental car counter) require you first make a claim with your homeowners policy.
My 2 cents.