I would look at Ikea storage systems. Great price and the furniture is good. I recommend either white or grey to work with the current furniture (if keeping) or if you are keeping the bed. The Hauga or the Hemnes would work well with the more traditional furniture you have. However, I would also look at what functionality you want, as any of them would work.
With the Besta system, you have a lot more color choices, but there is an upcharge for those colors. They have a really nice light colored Walnut that would look great with the cherry.
The Billy system has a lot of bookcases, but not a lot of other choices.
Since he doesn't care much and he is 16 (I get it, I had 2 teenage boys), I would get what is best economically for you and could be repurposed for future use in this room or another room in the home.
While there seem to be a lot of choices, you can quickly narrow it down, based upon price, color and the items you want.
https://www.ikea.com/us/en/cat/storage-organization-st001/?cid=a1:ps%257Ca2:se%257Ca3:US_ActivateConsumerLed_Behavioural_0AO_0en_Search_Brand_HFBMUL_0EM_IKE-IKE-067_IKEA_FY23_Google_CPSA_AOH_Text_Br_Exact%257Ca4:ikea%20closet%20storage%257Ca5:e%257Ca6:google%257Ca7:cq%257Cid:IKEA%2520Branded%2520GM%257Ccc:915
Q
Built in desk
Q