Credit cards for rehab

I'm about to start 2 rehab projects. I have 7 credit cards currently. I'm hesitant to open more credit cards to take advantage of 0% APR for 12+ months as this is just more credit cards and I also want to make sure I do what's best for my credit score as well.

If I don't open credit card then I'm borrowing money from heloc. what's best strategy? Any strategies I may be missing? Logic says open another credit card to avoid paying using heloc, but there's got to be better methods.