[New Player] Is there a way to search the flea market for attachments for a specific weapon?

Title. In this instance I've been wanting to run a lot of woods since I like the map, and to do so I want to put together a decent budget (150k, give or take) sniper, and was thinking of maybe going with the m700. Problem is, the default/starting build that I have that came with EoD seems to not be good enough so I want to mod it, but I have no idea what precisely can fit in each of the slots and there doesn't seem to be a way to like right clik -> filter slot on said slots either