Whether you have to have a permit ot not, build it according to a code. After all, the code is only a minimum and often is is better in the end to exceed the code. Even if you do not need a permit, you may not get power without an electrical inspection approval. - Same for sewer/septic.
Either a slab on grade or continuous footings below frost with a floating slab inside. If you go with a crawl space, footings should go below the frost line. Check a local code office for information - they will give you information even if you are not getting a permit.
Walls probably 8" block.
Reinforcement - depends on whether you are in a seismic area or not. If not, vertical steel (#5) with grout at all openings and reinforced lintels over all openings. Bond beam block with continuous 2 - #5 bars and grout for the top course.
Insulation - depends on the climate.
You should get someone to make up some simple drawings since you may not be familiar with many dimesnions and practices that make things easier and better to live with. If wil also make it more valuable when you go to sell or easier to work on if you modify it. If it is not built to code, you will regret it when you go to sell or add on to when a code will be in effect (there will be sooner or later).
For the exterior, coat with Thoroseal(waterproofer), not DryLok. Then you can coat with an exterior latex in the color of your choice.