Why not make it easy and affordable and attach galvanized steel downspouts to your steel gutters. You can connect them with stainless steel pop rivets.

According to one roofer, galvanized metal must be painted and maintained so that it doesn't rust. Copper does not have to be maintained. He is suggesting copper for the spouthead and aluminum for the downspout. Mainly because copper is stolen around here.

dusty-
I live in the Pacific NW where it probably rains a lot more than where you are. I don't do anything special to maintain or paint my gutters. My house is almost 15 years old and the galvanized gutters and downspouts are going strong. Aluminum and copper are going to have a galvanic reaction, but they do have the advantage of allowing the roofer to make more money off you...both now and when he comes to replace it in a few years..

Here is a link that might be useful: Galvanic reaction

>>galvanized metal must be painted and maintained so that it doesn't rustThat's false, good galvanized metal should last a very long time, if the time comes when it breaks down, [several generations down the road] you can paint it over for prolonging live.
If you do it before, it's a waist, in the contrary, paint will peal/lift and moisture will build up under there and corrosion starts earlier. Unless you hardly ever clean gutters and moisture is there all the time, then painting might improve life.

Copper is best.

I agree with konrad. However, as nice as copper is, I can't justify the expense. And as discussed above, don't mix metals in your gutter system.

Thanks all. I will discuss sticking with galvanized metal with the current contractor I'm talking to.