There is nothing wrong with an arc welder. I learnt to weld on one, and it just takes pratice to use them well. Yes you can weld exhausts with them. Hec thats all they used till migs became mainstream. ( I will confess, I am not much of a welder though)

I find the key to it is good quality rods, that are nice and dry, and thin. If my rods are a little old, i bake them in the oven for about 15 mins to dry em right out.

And i always have a play first on some scrap stuff so that I get the ampreage right.

Sure migs require less skill to get an arc, but you still need a steady hand, and praticse to get a good bead.

I guess I have a soft spot for my welder. It was my fathers that he bought in the early 70s, and it built most of the machinery on the farm. In saying that I also have a little gassless mig now that I use for the really fine stuff.

So in conclusion, yes the arc welder will do the job good enough. A mig can make an unskilled welder look better, and its eaiser on thin stuff.