I would still recommend buying a few modules at a time and allowing for a change in plans. My actual rack is much different than my initial plans.
I’ve argued in favor of the aesthetics being an important part of modular in the past. Just as guitars use flame maple tops and drums have glitter finishes, it’s OK to want your instrument to look cool too. With that being said, if it only looks good but doesn’t have the right parts for YOUR style of music and patching, it becomes an expensive attractive paperweight. I would advise placing function over form as you begin assembling your instrument. Use the thing, don’t just look at it. And if you buy a module that doesn’t fit in, sell it for a small loss and move on quickly to something that actually works for you.
That’s about the best advice I can offer. Let us know how you progress in the journey!