There are numerous ways that have been tested and approved to build a long-lasting shower. For the minimum height shower pan, you have a a few choices: pick up a premade one and adjust the size and placement of the walls so it will fit, or build one and use a surface membrane verses a traditional shower with liner. Both of those methods are more expensive in material verses a traditional one. The liner should go at least 3" above the top of the curb before there are any penetrations (i.e., screw or nail holes).
FOr long term performance, the waterproof layer (this is NOT the tile) must be sloped. For a traditional shower, the mortar must be at least 1.25-1.5" thick, and you need two layers with a preslope, liner, setting bed. Over a slab, you can fudge the thickness of the first layer a little, but shouldn't on the setting bed layer. You don't really 'pour' a shower pan, you pack it. Correctly mixed/proportion deck mud is about 5:1 mix by volume of sandortland cement, mixed with enough water to wet everything so it holds together when you squeeze a handful, but doesn't drip water. It's much like working with wet beach sand. You probably have about an hour to do one layer (then you'd let it cure overnight). With a level, some strips of wood, and a packing block, you can pack and shape it pretty easily...the materials are cheap enough so you can build a mockup and make a trial run and only waste maybe $20, so you wouldn't be out much if you wanted to try it.
Personally, I find www.johnbridge.com to be a good place for educating yourself on how to build a proper shower. Check out their 'Liberry'.
A surface membrane like Kerdi uses a special drain and mates with a surface waterproofing membrane that attaches directly to the drain. This means you only need one layer, their preformed foam pans can be cut, but aren't close enough to your needed dimensions to be viable. But, the membrane works just as well over a deckmud layer. The advantage is, deckmud is MUCH cheaper than any premade pan, and you can get exactly the size you need with the drain exactly where it is. All pans come with some predetermined 'optimal' position or the drain, which may not work for you.