DLASK is selling NR Bren 2s in 7.62x39 with mid/long gas systems. You can use 10 round pistol mags with them. This is unequivably the best 7.62x39 rifle on the Canadian market right now. It has everything anyone could need.
The WK181 is the affordable second choice for getting all the modern accessories on (optics, slings, bipods etc) but is limited to 5 round mags
The M10X has an in country warranty support, buuuut between buying from them and buying a WK181 I´d lean towards the the WK181, the M10X has just been too much of a variable in my opinion, ignoring the past of it´s entry to the market the rifle is something I´d wait another year on to see if it really has actually improved. Oh and 5rd mags only
The Type 81 looks nice but has bad iron sights, poor accuracy and by the time you´ve made any and all changes to make it have bipods, optics, etc. on it you´ve spent a lot more than you would have on a WK181 or M10X which come with those options out the door. It also only has 5rd mags. You can really enjoy one of these if you like cold war aesthetics and appearences but from a functionality point of view it´s lacking.
SKS, it´s got ok iron sights, meh accuracy and is highly affordable. Optics mounting solutions are slim but for the price you can get a pretty capable rifle for $1000 or less all in. Stripper clips are slow and fiddly and 5rd capacity takes out the fun.