Heather, I looked up the rose on HelpMeFind.

http://www.helpmefind.com/gardening/l.php?l=2.5777&tab=1

By clicking on the "buy from" tab there are a couple of nurseries listed, but who knows how current the information is. Quite a few rose growers have bit the dust or reduced their inventory in present ecominic climate. On the "comments" tab one person wrote this:

"Certified Roses is supplying this rose as bagged-and-waxed bareroots to Wal-Mart, at least here and now (north Florida, January 2004)."

I checked the sites of a couple of Canadian rose growers and neither of them had it listed.

You might want to post your question on the GW Rose Forum. If anybody knows of a source someone on there will.

Another option is you might be able to get cuttings from someone growing it and try to root them.

I'll be watching for it in my spring plant nursery visits and wish you the best in finding it.

Here is a link that might be useful: GW Rose Forum

Heather, if you are unable to locate 'Simply Irresistible' you might be able to substitute 'Secret' which is a similar color and very fragrant hybrid tea rose providing you perform a proper candle light ceremomy with such words as "The Secret is that you are Simply Irresistible" or something along that line ... :-) Secret is very popular and would be easier to find online.

Here is a link that might be useful: Secret on HelpMeFind