Uhhhhhh...I foresee problems. First of all, modular synths tend to have a specific sort of architecture; they're not put together with a "throw modules that look cool in a box, hope for the best" mentality. In fact, there's a very high risk of falling into the "sexy module" issue...lots of cool looking stuff, blinkenlichts und tvistenknobs, but you'll have neglected a lot of boring but essential modules in the process, resulting in a totally useless build that's then cost a pile of money to yield no useful results. And there are a LOT of important-yet-boring modules that have to be part of any build: attenuators, interstage mixers, OR-type summers, buffered mults (if you have enough CV destinations to require them), VCAs and the like.
ReBirth and Reason are NOT good starting environments for understanding what has to go into a proper modular build, since neither has you working at the module level on signal flow. Before proceeding further, I strongly suggest you do the following:
1) Get VCV Rack. This is a virtual Eurorack-type environment, and while things don't work precisely like they do in hardware, they do show how a build has to be put together, since the same signal path and architectural rules apply there as in a hardware build.
2) Study some classic modular and/or patchable systems, such as the ARP 2600, Korg MS-20, Moog's IIIc and System 55, the Synthesizers.com and other manufacturers' prebuilt systems, Roland's System 100 and 700, etc. All of these are successful designs, and still sought-after because they were done right. Notice how the signal flow works, what modules are incorporated, and the like. Make special note of the ergonomics, also; it might seem as if some panel space is wasted on some of these, but there are very real reasons why the various controls are located where and how they are.
3) Stay off eBay, Reverb, etc for the time being. That's just "modular porn", and it won't help you understand what you're trying to do. MG does a far better job of explaining what things do, why you might want them, why you also might NOT want them, and to explore how a build would work for you before dropping stoopid-huge wads of cash. You also get user feedback here, such as on this forum; commerce sites just can't provide that.
No one module will get you "where you want to be". That's actually a dangerous idea. Look instead at how modules interact in subsystems, and how those subsystems' signals get handed off in a modular environment. Saying that a certain module will achieve everything you need is like thinking that if you just had this specific, bespoke, boutique key on your tenor sax, you too would suddenly become John Coltrane. Ain't gonna happen. Do the work; throwing money at a problem without doing the work beforehand is simply expensive foolishness.