Re: PayPal header
I looked into this many years ago so my info may be a bit rusty but I believe that this IS possible, there is somewhere on your cart set up that says, 'create custom payment page', however, one word of warning... unless the image (Banner) you use is not from a secure site, (i.e. https) it will give your customers a warning message every time they go to buy an item from you so I wouldn't advise this if you can't ensure this.
You cannot simply change your paypal payment name though, trust me on this one. My account is in my own personal name rather than my business name, but this is because my bank account is in my name and not my company name (saves a lot of charges and trading as a sole trader I can get away with this!) When you transfer any funds from paypal to your bank account, if it's not the same name as your bank account then you may have problems.
Don't aim for success if you want it; just do what you love and believe in, and it will come naturally.