Lance: I make most of my own triggers, and a fair number of those are either twisted, have curled ends, or are pointed to a slightly-curved rat-tail. In point of fact, there are a helluva lot of plain triggers in extant medieval/Renaissance crossbows that are dead-plain, just squared or rounded off at the tip. Outside the variation of simply bent square, carried to a point or bent round at the nuckle, most are rather plain. I find such triggers boring, so tend to twist, roll or taper them, but in fact very simple triggers, like those sold by Alchem are pretty much the norm.
So you don't need fancy triggers to do authentic work. Fancy stirrups are even more uncommon, though many 'germanic' triggers are oval in section and have a pleasing 'T' cross-section that's very hard to reproduce.
As for not knowing how to make these things... well, you need something for a forge an anvil and a big hammer... then you get to work. There are a fair number of youtube videos on smithing that can help.