This might help

Here is a link that might be useful: azalea groupings

moril - Thank you for the link. Such beautiful groupings. Can anyone suggest azaleas that combine nicely with red rhodies? in zone 8? BC?

Some shades of pink and orange go well with red (yes, I have been painting the house) so compare those colors with your rhodie's. Since colors on the Internet may not match the real colors, I suggest you proceed carefully. Especially if ordering by mail. Perhaps you should visit an arboretum or gardens when azaleas are at their prime and get the names of varieties that match your rhodies' shade of red.

Here is a link that might be useful: Pictures of pink azaleas

I think white azaleas would be awesome. Check out the Azalea called 'Gardenia' Very cool.

As far as 'companion' plants go, you could go with low ferns: holly ferns, Autumn ferns, painted ferns. But a contrasting Hakone grass spilling out between the rhodies would be very nice as well.