Greg congradulation on your purchase. Accuracy on stock HK93 isn't all that great, especially with stock trigger. I'd get williams trigger work for $60 to lighten the trigger first.
I personally think ACOGson HK rifles sit too high. Not to mention they are expensive.
some better options:
Kac RAS forearm with Aimpoint attatchment ($800).
G3 Hensoldt surplus X4 scope with mount ($400, good deal).
I now use Zeiss Diavari DA 1.5X6, the best, but very expensive.($1200-1500)
If I were you, I'd stick with iron sights, and with money you saved, keep saving to buy HK91 (which I like better than HK93) and put less expensive Hensoldt X4