Hi Mab
In our salads we mainly have cucumber, celery, raw onion (red is nice and sweet) and/or spring onion, capsicums (bell peppers) and tomatoes. We love mesculan salad and also cos lettuce salads.
I've had a hard time finding non-starchy tomatoes around here but they are usually fine. And if you can tolerate dairy then add a little hard cheese. Jon can tolerate a bit of cheese but if he starts eating it every day it seems to cause problems.
Coleslaw is also a good idea and you can make it more interesting by adding more things. We have green cabbage, red cabbage, some grated carrot (can usually get away with raw carrot as long as not too much), finely sliced celery, coriander, red onion or spring onions. I use either Aioli (garlic mayonaise) or Best Foods Real Mayonaise - read the labels on commercial dressings like this. Steer clear of any with "thickeners" added. Additives in the 1400 range are starches.
I've heard of some people having problems with onions - esp if caramellised as this tends to make them hard to digest. Jon has them raw or lightly cooked with no problems.
I guess if you are worried about adding so much new stuff at once you could start with a base salad and just add a new ingredient each day and see how you react.
Hope this helps. Don't give up, you're doing so well and it's a lot to take in all at once. It took Jon about 3 months just to get it sorted what he could and couldn't tolerate.
Chelsea