Once Greece properly integrates this new land, they should focus on naval power.
Reason is, that the only country that Greece should think about going to war with, hell the only country they border, is the Ottoman Empire. However, no matter how deeply Greece invests in its army, it will always be a bad matchup against the ottomans. They are simply too large a country, with too large a population, and too low infrastructure. The greeks can't match their manpower, and logistically they would be hard pressed to push into ottoman territory, and they simply could not get far enough to force the turks into peace. The more they push into Macedonia and Albania, the worse the logistics, and the wider the front, pushing the advantage firmly on the Turkish side. To put it simply, unless the turks have several other major enemies to deal with, a greek army isn't going to march on Constantinople any time soon.
However, the naval game is an entirely different matter. Here the greeks do stand a chance of matching and surpassing the Turkish navy. If they can catch it out of position early in the war, and maintain the advantage, Greece could close the southern Aegean easily. With enough investment, they could even think of locking the turks out of the entire mediterranean, relegating them to the Sea of Marmara and the Black Sea. A large blockade of this scale would cause terrible damage to the country the longer it drags on, and could force some serious concessions. As long as the army is not neglected, it shouldn't be hard to create a force that can hold the border against a larger Turkish army, since the new border is quite defensible indeed.
Anyway, that's what I see as the best strategy Greece could adopt in a 1 v 1 conflict with the turks.
I admit another school of though is that as long as the British prop up the Ottomans, the navy should be mostly ignored, as they can't match the UK in the sea unless they are highly distracted in multiple other theaters. In this school of thought, Greece should plan to work with the Russians to have a two-pronged attack in the balkans. With half a million Russian troops in the north and 150k-200k greeks in the south, it could divide Turkish attention and logistics to the point they can have a swift conclusion in Rumelia before the inevitable British blockade takes its toll. Reason I wouldn't support this strategy is because it presupposes war with England. And as they are our biggest trade partner and investor it's hard to see the benefit in such a conflict. If the turks are falling apart to the point where we could take enough land to justify going into recession for a few years and crippling future growth, then we could just take the land diplomatically by threatening war, and get the best of both worlds. Which is exactly what happened in the recent update. And while this strategy is slower than the Russian "total war against the turks once per generation", it will mean that by the time we are ready for the coup de tat, and crushing them once and for all, Greece will be a rich and prosperous state, rather than one which has been bleeding for 50 years to get to where it is.