So you want to fund the business using credit card debt?  Not always a good idea, as credit lines can easily get reduced as issuers see that your utilization is way up and/or if you have to miss a payment, you might get hit with penalty rates on APR.

Have you also tried other approaches, such as getting a small business loan (or a HELOC if you own property).  Anyway, good that you explained what you need, so the emphasis needs to be on cards with good introductory APRs, and low balance transfer fees, and not necessarily those with the highest CL and reward structure.

You didn't list exactly which cards you have, so advice might duplicate.  For example, Citi Simplicity is often mentioned in this context, 0% purchase/BT for a long time, but is that one you already have?