RB1000 was excellent for IPsec as it had encryption in hardware. What are the options for new customers now as the RB1000 is out of production and the RB1100 does not have encryption in hardware?

We didn't recall the RB1000, so if you have one, you still have it. And some distributors also carry it.

I have six customers that potentially wants 14 RB1000's in total. The norwegian distributor does not have any left in stock. One is even considering replacing a cisco 3500 with a RB1000 because of the IPsec performance. I just don't know what to recommend the customers now as the RB1000 is not available any more.

Some Distributors still have RB 1000 Desktop units in stock, but none of the Rack-mountable ones.
It's probably better than nothing, so try getting some of those. Maybe even try to buy some in Germany or other countrys in Europe, I am quite positive you will find some.