Do you have an example of what would be "uncomplimentary" to see what you're trying to go for here?
...aren't most charts complimentary?

You mean like a couples chart?

Is that what you mean?

Make edits. How about digging up some old versus charts They were all so easy that difficulty shouldn't be an issue.

The Least 100 Seconds on Heavy and Standard and/or Basic.

Senorita. An old favorite on standard. An old favorite on heavy.

What machine anyway? SN2? Or Extreme? or ITG?

And yeah, what do you mean by 'complimentary'? I didn't think most charts really complimented each other, I would be more concerned with finding actually good steps for both difficulties first.

Might try Era, Dynamite Rave (the original one), and Dam Dariram, I believe I used to play these a lot in my days of standard and I think theyre good. Lets Groove and Spin the Disc are both good super easy Heavy charts you could both do too, also old favorites

What scott means by "complementary" charts is two different difficulties of a song that play like couples charts; They are vastly different in style but sound "cool," for a lack of a better term. 

Thanks James, I was having a difficult time expressing what I meant by complimentary.

If you want to know what I consider a "complimentary cahrt", start up 2-player mode in stepmania and choose Sync on Heavy & ONI. Turn autoplay on and listen to the way the steps work with each other. The combination of both steps played simultaneously sound pretty awesome. I'm trying to find some other charts that might be similar to this.

Btw, thanks for the suggestions so far, I'll give each a shot and see how they work out for us.

And yes, I suppose this could be considered a "couples" chart, but I'm not wanting to play on doubles play, my GF is a high score freak and would probably rather play 2P versus on Standard.

Probably Extreme, but ITG2, SN2, or anything else would be useful.