If you are serious about day trading I strongly suggest you take $5-$10K and find yourself a fairly reliable Prop firm. You'll get at least 10:1-20:1 leverage, your commissions will be much lower (at least on a per share basis), and you will have fast direct access to the markets.
As far as your current broker, if they don't accommodate you with this "margin paperwork" issue, I urge you to find another one ASAP. I personally have not had experience with a retail brokerage in a long time, however, to me your situation sounds like B.S. from their side. From what I remember, not having a margin account means you can't short-sell, you can't borrow $$$ from the broker, and you have to wait around 3 days for your trades to settle. When I just started out I had an account with Datek (now Ameritrade) and when I initially did not have a margin account they just did not allow me to execute trades until they settled. So IMO it's their fault for even allowing you to execute when you in fact did not have a margin account. Obviously, since you have over $25K, the patterned day trader B.S. is not an issue...
So if they don't work with you just sit on your hands and wait until all of your trades settle, once they do, do yourself a favor, and open at least a second account if you intend to do short-term trading. From my experience, using the same account for investing and trading is not a good idea anyways...