Upgrade My Denon DP80 Tonearm

Hello!

So for the last year or so, I have been enjoying my Denon DP80 with a DK300 plinth, DA 402 Long tonearm, and Denon 103 cart. In my (now current) interest in looking at sonic improvements to this set up, I read that the 402 a low mass tonearm and not well suited to the 103. So I began my due diligence on a Denon tonearm that would not require me to drill any new holes in the plinth...a drop in exchange of sorts. Google AI searches suggests that the 307 and 401 would fit this bill, but they look like shorter arms. For those with Denon knowledge, What would you recommend be my next tonearm pursuit, and what about a head shell? The 402 appears to have a proprietary (low mass) one integrated into the arm. I thank you in advance for your time in reading and replies...may they be kind and related to the topic at hand.