You can order a 17hmr accessory barrel with sights for an extra $50, but you can't buy a complete new rifle that way. Iron sights on a 17hmr wouldn't be the best way to get the full potential accuracy out of the 17hmr, but different strokes. Ammo is well over $10 a box now, as high as $13. If you want iron sights, I'd just get a 22Lr sportster or even the 22mag.
Tim