Hello magento community,
You guys know some extension that hide shipping and payment from checkout and allows the admin define shipping price / payment options?
What you are looking for should already be included.
There are Amasty extensions which I've used in some of the previous projects
You can use them to configure any kind of restrictions to payment methods / shipping methods. Also, you can do limited restrictions in Magento Admin, check System -> Configuration -> Sales -> Payment methods or Shipping methods. There you configure them, but if you're not satisfied with flexibility, buy extensions.
Unfortunately my current webstore has more than 5k registered products with various dimensions, making a hard task to find/create a good extension, specially on my country that has few shippment companys.
With all these barriers, the short way to put by webstore online is turn the shipping and payment a manualy process to the admin.