Well, since I don't know where you are, or how well heucheras do for you, I would say you should start small to make sure you're not setting yourself up for mass disappointment.

I wouldn't do it...mine tend to slowly decline over a couple of years.

I have 3 in another bed, I'll see how they do this year before I do anything major. Thanks!

Heucheras tend to hang on pretty well in my climate although I would not consider them to be a very long lived perennial. Except for a few varieties, 5 years is about what I'd expect.

When I was a nursery manager, we did a mass planting of heuchera in a huge (4' across) flattish concrete planter as a customer display. It looked great (and helped to sell a LOT of heuchs) for a single season. Then a case of heuchera rust spread through the entire planter and we had to ditch them all. FWIW, I have never had rust infect any singly planted heuchs in my garden but a mass planting seems to allow the pathogen a free reign to spread wildly.

If you live where there is frost, they tend to heave out of the ground and die over winter. i gave them up years ago.

Anywhere weevils are present heucheras are favored targets, as are primroses.

Wow folks really don't like heuchera huh?

If you choose a cultivar that's off patent or never patented you can propagate by divisions, almost like hostas. Making it so when one does do well you can make more of it. That's great if you like doing that.

The good news is that any of the cultivars is going to offer contrast to the species form you are planting. So I would try and find the oldest cultivar you can, maybe a Dale's Strain, Palace Purple, Plum Pudding, Autumn Bride and Silver Scrolls all seem to be available in the trade despite much commentary on older varieties disappearing. Of the new still-on-patent ones everyone seems to like Caramel. Planting in the spring is better than in the fall for overwintering, but of course they sell well in the fall too.

I would also acknowledge that some are going to be like annuals and a long narrow row is going to have some that grow big and some that don't come back. I am assuming your planting area is mostly shade and you are growing in zone 7 where it gets hot in the summer otherwise you want advice from someone else (and writing where you are is helpful).

Here is another assumption: you are specifically looking for a native shade plant where the foliage is interesting. You might want the native Dicentras! Other plants to look at (not native to North America) to see if they can help diversify your planting: Astilbe, Hosta, Acanthus, Alchemilla, Carex.

Many of us like heucheras perfectly well. But most of the newer, brightly colored varieties tend not be very long lived under the best of circumstances. And they do have a few issues - crown extension/frost heaving, rust, little tolerance for high humidity and weevil damage where those are common garden pests. And deer consider them just a brightly colored salad bar so be aware of that appeal.

My best performers are Green Spice, with highly patterned and seasonally colorful leaves and most of the very dark purple colored ones (Obsidian, Forever Purple, Blackberry Ice, Frosted Violet, etc.) and these do best for me in pretty much full sun but I then live in a cool summer climate

The original 'fancy' Heucheras were better plants, but it seems like a certain wholesaler would rather us purchase their more recently hybridized, short-lived ones. More profit that way! 'Pewter Veil' was one of the first perennials I bought, probably, and it grew well in Virginia for many years and spread fast enough to fill in a small bed under a dogwood tree. Good luck finding it these days. When I had to 'rescue' a few plants from that garden in 2003 because my parents were moving, it was one of the last I would have thought to worry about. Wish I had dug one up now.

Over the years I've tried quite a number of different heucheras, and currently the only one I have left is a good old-fashioned Purple Palace. It's growing in a corner of my yard that gets virtually no sun and it keeps coming back year after year.