We can consider the question of punctuation once we've established the text. Your Wikipedia quote represents some modern scholar's attempt to reconcile the two main sources for this fragment of Pindar (110). The first source is Eustathius' commentary on the Iliad (3.186.18), who quotes
γλυκὺς ἀπείρῳ πόλεμος.
πεπειραμένων δέ τις ταρβεῖ προσιόντα.
The second is a longer version in Stobaeus (ecl. 4.16.6):
γλυκὺ δὲ πόλεμος ἀπείροισιν, ἐμπείρων δέ τις
ταρβεῖ προσιόντα νιν καρδίᾳ περισσῶς
Metrical considerations caused the modern editor to take the δὲ (which only means "and" or "but") from Stobaeus and contract it to δ' before the singular ἀπείρῳ ("for the inexperienced one"). Otherwise, he follows Eustathius' word order, but then adds the final three words from Stobaeus, which are not in Eustathius.
In any case, you see how punctuation is an exclusively modern concern. And if you're going to use upper case, it won't be appropriate to use punctuation at all. Or contractions. So the Wikipedia version (with the usual Wikipedia misspelling corrected) would look like this:
ΓΛΥΚΥ ΔΕ ΑΠΕΙΡΩΙ ΠΟΛΕΜΟΣ ΠΕΠΕΙΡΑΜΕΝΩΝ ΔΕ ΤΙΣ ΤΑΡΒΕΙ ΠΡΟΣΙΟΝΤΑ ΝΙΝ ΚΑΡΔΙΑΙ ΠΕΡΙΣΣΩΣ
For a font, you'll probably want Lithos Pro, which you should check out on the Web.