HI Elaine
The only way to find out about the spelt and Rye bread, is to test to see how it impacts on your BG's, testing at one hour and two hour after you eaten (the one hour test to see if it spikes high before dropping back at the two hour) then depeding on your results, it may be that you'll fine, but perhaps it may turn out that you have quite a high spike.. Options then would to either to stick it on the 'NO' list of foods.. or perhaps seeing if having a smaller portion of it, resolves the spiking..
As to foods for those peekish moments
Look for carb free type's of foods or that have very small amount of carbs..
Some nuts, perhaps some cheese, even sugar free jelly with a dollop of cream etc
Other ensure that it has either a small amount of carbs or slow burning carbs (this is where the GI diet index load can be helpful)
I do often enjoy Tucks topped with cheese, as these have very low amount of carbs around about 3g's worth if I remember rightly off hand..