Is there a not too expensive (less than $¹⁰⁰⁰) and good linear tracking tonearm that I could mount on my SL1200MK5?
Depends on what you mean by "good". If you mean one that works reliably and fits on the table then maybe, yes, you can probably find one. If you mean good compared to what the same $1k will buy you in a normal pivoted arm then sorry, no, but thanks for making me laugh.