u/Accelzero

so atm I'm a level 6 ascendant dragon monk in dnd 5e but I'm trying to decide on what I should do or save my gold towards for my next few levels. I have a few ideas but I'm not sure what would be the most useful.
-delver claws: I get to burrow in the ground and blindsight
-sun blade: increases my damage to d10 and get a source of radiant damage, and I can make it my dedicated monk weapon
-take a level in rouge: get longswords for damage increase and expertise with two skills.
or just take weapon master at level 8.
what do you guys think would be the best route to focus on?