I would look at the cost of the formwork option (either made yourself or hire) vs the lay slab and besser block filled with concrete and reo. Like Stix has suggested and defitinatly on a concrete slab as Stix has also mentioned. You can put the first layer of bricks on the slab as it is nearly dried and push the reo into it. Again as Stix has mentioned this just cuts down the drilling and chemset. You are or should put in a concrete roof and really the best way I can think of it is to use form ply really well supported from the floor.I have seen it done in third world type countries and the use just tree type supports spaced at about every 500mm then set your reo and perhaps some steel beams and pour the concrete on top.
It Really is not as hard as it sounds. Using the formwork option Lay the floor slab first poke some reo into it where the walls are going. I made a steel frame first of the whole building but it wasn't necessary. I then welded reo between the posts and the put the form work around it all. I used a concrete pump truck for the walls as I was doing 5 cubic m at a time. But if you were doing it in smaller sections maybe not needed. I hired a vibrator and just dropped it down the walls as they were poured. leave some reo poking out the top of the walls to tie in the roof. Cut a lot of cheap 4*2 supports for the form ply. then put in your Reo and any steel girders depending on how strong you want it. You can also make like foundation beams in concrete across the roof. Look at underground car parks.
Tip brush all the formwork with diesel makes for easy removal and smooth finish.