Online credit and processing/merchant accounts

I am setting up a small business, and I set up a website through godaddy (total cheapskate here). But I want to accept credit cards. They have their own merchant account, which could be the simplest thing to do; but I would rather keep my options open. Does anyone know if I can use other merchant accounts on their site (they also have some "quick shopping cart" but since they are trying to peddle their own service, they are not clear on how to let outside merchant accounts in). Finally, do I have to have a separate bank account, or does a merchant account take care of that too? I came across Chase Paymentech (I use Chase for my personal banking), and I'm not sure exactly what this is, other than that it is related to Online shopping.

Anyway, thanks for reading this (and any of my other sorry requests). If you've had good experience with a merchant account , please let me know. I don't know what to expect for sales...I would need $500/day of sales (by the 6 month or so) at least to keep the company solvent. Of course, it could be $0 in sales and a total bust, too.