Venosa violacea is outstanding and a type III.

The President and Guernsey Cream are type IIs that are more vigorous and reliable than some.

Asao fades badly in full sun or hot afternoon sun.

In your zone you should probably pair IIs with IIs and IIIs with IIIs. In warmer zones many prune IIs as IIIs but you are colder and that might really hurt your bloom times.

We all have different color preferences, so it's hard to give advice, although grouping 2's with 2's and 3's with 3's.

Do you have tab browsing? Meaning, you can open multiple tabs in a page.

If you can, do it, or just open multiple browsers. Go to Clematis on the Web in each browser. Bring up each clematis up in it's own browser, and then jump back and forth between the tabs until you find combinations that you like.

I like the lav-blues with yellow roses. Or were you wanting combos of clematis only?

I'm wondering if Asao would be good with a climbing Angel Face? They weren't in bloom at the same time this year.

Love Venus Violacea with climbing Royal Sunset (soft orange).