You don't have to begin with a furious dedication with all sorts of mods and whistles. That can come one step at a time, if and when you feel like it.
At present, I went back to strictly "stock", removing the extra weights and playing it with my SME 309 in strictly "stock" condition. The Step-Up is the "budget" Denon AU-300-LC with very decent results, and the Parasound preamp is in strictly "stock" condition, also.
I do not doubt that the DL-103 can be modified to glorious conditions! But right now, my strictly "stock" unit makes me happy as all get out, and I am not even considering any modification at all. My ears would possibly not hear the difference at my ripe age, and I have developed great respect for its cantilever and special conical tip. No, make that "am amazed with its conical tip". And I have developed a fear for my financial budget, also!
So, go easy on yourself, and take it at your own pace. The SL-1200 is no longer built, I believe. And if you get one, the fluid damper IS a great idea! And don't add any weight to the headshell. You might like it!