Roksan uses "standard" Rega mounting geometry. You may drop in any Rega RB250/300/600 or Roksan Nima/Tabriz/Artemiz.
The Rega RB700/900/1000 with their 3 screw fixing can be easily installed without modification to the table.Other tonearms brands such as the Moerches may also be used without the need for redrilling.
Lovely turntable, btw.
best,
Ken