conner, for cycling the rock, yes you can use the 1262 in a large brute garbage can with heat to get the rock going...this is a great idea, by the time you are ready to setup your system, your rock will be cured and live and you will have a shortend cycle once you fill the display. As mentioned, for every piece of equipment you need, there are several options or ways of doing it...example:
Flow - can be done via closed loop or internal powerheads. Internal powerheads also come in various flavors, like tunze, vortech, koralia etc
light - T5, LED, Halide, PC...
what's the "best" for one person isnt always the best for another, so it pays massive dividends to research other builds, but make sure you dont only read the setup section of a build, you need to see how the tank does down the road and what lessons the reffer learned in his/her build or what they say they would do differently. also you should not only be thinking about hardware, but processes as well, most importantly, how will you do water changes....this is one of th emost improtant maintenance items, and often tanks are setup without taking into consideration how new water will be mixed, stored and then transferred to the tank as well as how to get rid of old water...so think about maintienance too because the easier it is for you to conduct maintenance, the more you will do it...some other things to cinsider, is the floor where you will put the tank level? if not how will you level it? is there access to water and drains near the tank? if not will you use buckets or setup some hard plumbed lines...theres more to it than just buying the gear and filling it up...take your time, there is soooooo much great info here, take advzantage of it...
good luck to you, and feel free to reach out, i too have a 90 running a mixed reef.