oscommerce shopping cart fix

I need 2 things done: 1. Finish Placing a pixel from an an affiliate network in the shopping cart....Currently the pixel works only when you choose check or money order selection, but not when the purchase is made with paypal....when the purchase is made with paypal, the pixel that fires is from another network which i am no longer live on, so something is wrong there and i need someone to figure it out...the work is half done, just need this last part fixed. 2. Right now when i go to make a purchase, i choose the object, click add to cart and then quick check out, at this point it takes me to either sign in as a user or create an account...once i either sign in or create an account i am then taken to the homepage of the site...this is what i want to change, instead of being taken to the home page of the site the user should be taken to the shopping cart. I am looking only for people with extensive oscommerce experience and who have placed tracking pixels on oscommerce sites before