Almond flour and coconut flour are the main substitutes, a bit pricey (shop around and look online, i've seen almond flour for $20/kg and i've seen it for $80/kg.......
Hundreds of recipes on line, but mileage may vary....
If you have a blender you can make flours from SCD legal nuts and seeds, this is cheaper and it is much fresher (nuts oxidise much faster once ground)
My experience is that almond flour and coconut flour can make great cakes but very average breads. A light touch is needed (folding rather than beating)
Coconut flour is extremely absorbent so a little goes a long way.
.................but can i just jump in with something you probably don't want to hear?
Most people seem to switch from a diet to high in grains to a diet to high in nuts, replace sugar with honey and wonder why it isn't working (and then come on to forums to tell everyone that SCD doesn't work, but that's another story).
Just eating foods from the SCD 'legal' list is NOT the same as doing the SCD diet,
It may have great benefit, and might be enough, but strictly speaking, SCD is an elimination diet,[1]
The diet is reduced to a bare minimum of foods perceived to be safe[2], and then food are gradually reintroduced, one at a time, to see if they are tolerated[3]. If a food is not tolerated then it is left out of the diet until it is retested at a later stage.
On top of this there are four SCD legal foods that should be eliminated (and reintroduced/tested) if the diet doesn't work for you[4]
SCD is only one option, and rather that repeat myself, have a look at this post if you are interested in SCD and similar diets
http://www.crohnsforum.com/showpost.php?p=875210&postcount=4
[1]
"This is accomplished by beginning the diet with extremely easy to digest, natural foods. This “intro diet” starts the healing the process and then more complex foods are added back to the diet very slowly. By carefully adding foods back to the diet the Specific Carbohydrate Diet is individually tailored to each person’s state of injury and digestion abilities"
http://scdlifestyle.com/about-the-scd-diet/
[2] The SCD Intro Diet
http://pecanbread.com/f/how/introdiet.html
[3] Properly Introducing New Foods on SCD
http://scdlifestyle.com/2013/07/introducing-new-foods/
The Stages of SCD
http://pecanbread.com/p/how/stages.html
[4] The Four Dark Horsemen of SCD (What to Do When the Diet Isn’t Working)
http://scdlifestyle.com/2011/03/what-to-do-when-the-scd-diet-isnt-working/