I'm from the US and help support a friend with tech issues who lives in Auckland, NZ with Vodafone DSL.
Her modem is currently dead and I wanted to look into setting her up with a similar setup as mine. A DSL modem in bridged mode and a router running DD-WRT for all her routing an Wifi needs. Her previous two DSL devices were modem/router combinations and the WiFi / router features were not very good (issues saving settings, WiFi incompatible with her S5 phone, browser admin interface not working with Windows 8.1, weird one I know, everything but the router admin interface worked, etc.).
From the research I've done the best choice for a modem is the DrayTek Vigor 120 setup in PPOA/PPOE bridged mode and a good DD-WRT compatible router in her price range.
I personally use an Asus RT-N16 with DD-WRT for my needs, and have half year+ long uptimes with extremely heavy use. Unfortunately the Asus RT-N16 is hard to find as it's been replaced with the RT-AC66U, priced at $280-$350 NZ dollars, which is out of her price range.
I'm looking for a DD-WRT compatible router in the $150 price range, thanks in advance for any recommendations anyone can provide.