Well i'm quite the newbie and not sure what else I can use for icing the cake? Buttercream can be a lot sometimes, maybe some sort of whipped icing. But then I'm not sure if I can get a smooth finish. Not sure what else I can use. The next cake i'm doing is going to be chocolate for one tier then vanilla for the other. Also ideas for fillings? I like the idea of a fudge filling but I'm not sure of a good recipe.

Thanks in advance.

I've used whipped topping mixed with melted Baker's Chocolate and I can usually get it just as smooth as my BC. I don't know how just whipped topping alone would do and also I don't think it would work well under fondant, it's super soft.

There's always ganache for filling AND covering!

There are non dairy whipped 'topping' type icings that can be purchased at places like BJ's; Smart N Final; maybe Costco or Sam's Club. One is "Frostin Pride"; and another is "Bettercreme" by Rich's.
You just spoon the semi-fzn liquid into your mixer and whip it until it forms a peak. They smooth on very easily.
There are also many, many different types of buttercream to try. Check out our recipe section to try some of them. You can find some filling recipes there too.

I personally like to use good quality canned pie fillings, jams and jellies. Either straight from the jar or mixed w/b'cream.

There is a thread on this site for gourmet WASC recipes by macsmom that give many,many different cake and filling combinations ideas.