The DS SA-58 is a nice rifle, looks a lot like the 'normal' FAL. Depending on the configuration will give different ergonomics, etc. I have played with the DSA SA58 18" PARA style rifle and while heavy a nice build. It takes the metric style mags, and uses some of the same metric style hardware.
At the time I had my hands on the hardware I did not have access to ammo or a place to shoot. My opinion is I rather have a new build over a metric parts kits with mis-matched parts. The rifle was picked up via Aim Surplus and was about discounted 400 off the list price. For the price that was paid I thought it was worth while hardware. A bit heavy to lug for deer hunting, but will up to the task. With the adj gas port (not sure if feature on all models), you could dial in what is needed to handle different ammo.
Common hardware configuration
16" Premium Traditional Profile Barrel.
4150 - 11595E Mil-Spec Barrel Steel
Chrome Lined Chamber & Bore
Barrel Features Bi-Pod Cut & Front Sling Swivel.
Barrel Threaded 9/16x24 LEFT.
7.62 X 51mm NATO.
4140 Fully Machined & Heat Treated Cast Steel Type 1 or Type 2 Receiver - Carry Handle or Non Carry Handle Cut.
Traditional Metric Cocking Handle Included.
Belgian Style Combo Device Flash Hider.
U.S. Made Glass Filled Nylon Pistol Grip.
U.S. Made Glass Filled Nylon Reinforced Full Length Handguards.
Traditional FAL PARA Folding Buttstock.
Light Weight Alloy Lower Trigger Frame.
20 Round Metric Magazine.
Owners Manual, Hard Case & Sling Included.
Matte Black Duracoat Finish Included.
[ full 100% in the US of A, so it not an import 922r rules don't count]