Definitely appreciate the advice. I did try the R size but my arms were way too long. I did take a look at the separates on the website and given that I am looking for a solid grey suit the only possible option is the napoli dark grey pinstripe which is sold out in my size sadly. I really would like to stay at the 500 range do you guys know of any other options comparable to SS.
The Lazio is like a slimmer Napoli with bigger lapels and more narrow shoulders. If the 46L feels comfortable other than the too-big shoulders, that could be an option.
I haven't found any brands at the SS price point that I'm satisfied with quality-wise. I've read good things on sites like Dappered about J. Crew (which now has the athletic Crosby fit, and is only sold in separates) but I sold the only J. Crew jacket I ever bought ever I found SuSu.
With your build, it may be worth saving up for a Kent Wang MTM, which is around a grand but highly recommended on this site. I'm planning on doing that sometime in the next year or so.