Question about Low-Mid rogue weapon choices

[Macha]

Hello guys! I am starting a Rogue and have a question about weapon choices.
I currently have a Trak tooth (10/20) and a 9/24 offhand which will be replaced.
I can probably afford as much as a locustlure...
My question is this, should I use 8/17 in main hand and 10/20 in offhand for damage bonus, or 10/20 in main hand for Backstab dmg?
Also, if I am using 10/20 main hand, is there a comparable offhand similar to locustlure for around the same price? I think Jade Mace is a bit out of my price range...