I struggled to get Arrma or DEX8T shocks (or any parts for the DEX8T, for that matter), so I invested in some Tekno ET48.3 shocks. These shocks have 4mm shafts (vs. the stock 3.5mm), a super-smooth action and have parts support.
I written this in a few other posts - Dollar Hobbyz have the Tekno ET48.3 shocks available as a full kit (shocks, bodies, caps, shafts, seals, springs, cap bushings, etc.), for $35-40*: