water is just a minor part of all of this. i feel that you are almost wasting your time if you go with water first. in any instance, you need bacteria for the water to cycle, and without something for it to live in (rock and/or sand), you arent going to cycle any faster, in fact, i would say that going straight water without rock or sand is just wasting energy.
if you are going to be taking time due to budgetary constraints,i would definately do at least rock first.
personally, i would say to just buy one large raw shrimp and throw it in the tank. let the ammonia rise, and let it all happen naturally. after all, if you ready to allow a large amount of time anyway, this wouldnt be a bad route. you could do the turbostarts, and whatnot to speed it along,, or you could just go the natures way and allow it to happen on its own. up to you really