Reddit reviews A Reader's Greek-English Lexicon of the New Testament (Zondervan Greek Reference Series)

Most editions of the NT don't include Loeb-style facing Greek and English texts. The most popular editions include Greek-only with an apparatus, footnotes, and dictionary. A Reader's Greek NT (amazon link below) has the best footnotes for the best price (mostly just uncommon words). There's also an interlinear lexicon available, if you want the extra help. It speeds up ease of reading, with common words listed by book and chapter, but you may not need it (link below).

As far as dialect goes, most people find Attic easier than Koine. The exception is that some vocabulary is context-driven, with meanings which are specific to the NT, Septuagint, or both (which is where Kubo is useful). Sometimes, authors use Hebrew expressions translated literally into Greek. I would start with John, and I John (and Mark is probably too easy), if you want to get a grasp of the style. Move into Luke/Acts if you want something that more resembles Attic style narrative (i.e. harder). Hebrews also resembles Attic grammar in some ways, but contains more Hebraisms.

If you are stuck on Greek/English interlinears in the Loeb style, you might want to consider reading Flavius Josephus (available in Loeb). His works on the History of the Jewish War and Jewish Antiquities use an Attic/Koine mix that might be more useful than trying to slog through new NT vocabulary. The Apostolic Fathers, which are post-NT Christian authors, are also available in Loeb, and they have similar themes and vocabulary to NT.

Ultimately, I would not recommend reading the NT unless your goal is to read the NT. If you want to get better at reading Attic, go read something written by native Athenians (Xenophon, Plato, etc.).

Links:

Reader's NT: https://www.amazon.com/Readers-Greek-New-Testament-Third/dp/0310516803/ref=sr_1_5?ie=UTF8&qid=1542997817&sr=8-5&keywords=greek+new+testament

Sakae Kubo: https://www.amazon.com/Readers-Greek-English-Testament-Zondervan-Reference/dp/0310269202/ref=sr_1_1?ie=UTF8&qid=1542998398&sr=8-1&keywords=sake+kubo

Josephus (War I-III): https://www.amazon.com/Josephus-Classical-Library-English-Ancient/dp/0674992237/ref=sr_1_3?s=books&ie=UTF8&qid=1542999070&sr=1-3&keywords=loeb+flavius+josephus

Apostolic Fathers I: https://www.amazon.com/Apostolic-Fathers-Vol-Ignatius-Classical/dp/0674996070

The whole half of the sentence is kai ho logos en pros ton theon kai theos en ho logos.

You are right, the ho before logos makes it more definite in focus than theos, which makes it the subject of the predicate noun. This means that the correct translation, if you were writing an exam for early Greek classes, is "the Word was God," not "God was the Word." It is because logos is the subject that the definite article was likely left off of theos, but you would need to argue this based on context

We are talking about two distinct clauses here. Grammatically, there is no reason to translate this as "and the word was with [the] God and the word was [the] God." You could translate this as "and the word was with [the] God, and the word was [a] god."

In fact, if taken in isolation, the latter would probably be a better translation. If, for example, you read the sentence kai ho oikos en pros ton anthropos kai anthropos en ho oikos. the slightly better translation would be "and the house was with The Man and the house was a man."

So, in summary, greek grammar doesn't tell you one way or another if the second clause should be read "[a] god" or "[the] God." It is a judgement call the translator needs to make based on context. And the context is glaringly obvious (IMO) that the correct translation is "[the] God." However, that can't be backed up using grammar, only allowed.

Are you teaching yourself greek, or taking a class? Might I suggest getting this if you are? It is a unique resource that is by far one of the best things you can own if you want to start reading the NT quickly.

Usually what happens is you memorize a whole lot of words , but never get all of them down. Naturally, you focus on the words you will use the most (I memorized all words appearing 25 times or less in the NT, if I were to do Greek again I would limit it to words appearing 40+ times). The problem is, every few clauses or so you encounter a word you don't know and waste lots of time flipping through or typing into a lexicon. This book does away with that. It has every word appearing 50 or less times in the NT. The catch is, it puts these words in the order in which they appear. So, if you have all the words appearing 50+ times memorized (which you really should do) and are translating Romans 5, all you do is open up this book to Romans 5. Now, every time you encounter a word you do not know, it will be the next word on your list. Seriously, I cannot recommend getting this book enough If you are going to spend serious time in the Greek NT, it will save you hours and hours and hours of useless work. </tangent>