Hi, Bart,
No less than three publishers produce Reader’s GNT’s. Zondervan has two editions:
http://www.amazon.com/Readers-Greek-New-Testament-2nd/dp/0310273781/ref=sr_1_1?s=books&ie=UTF8&qid=1429710101&sr=1-1&keywords=Reader's+editions+greek+new+testament
http://www.amazon.com/Readers-Greek-New-Testament/dp/0310248884/ref=sr_1_3?s=books&ie=UTF8&qid=1429710101&sr=1-3&keywords=Reader's+editions+greek+new+testament
The plus with these is the binding of the books, lightweight paper and a nice fake leather cover. These books feel great in your hand and you can roll them up like newspapers and put them in your coat or your back pocket. The draw back is the font. The font on the first edition is slanted, the one on the second edition has thin and faded letters. The first edition font, though, is fairly large.
UBS through several publishers has their own edition, available in many formats, from paperback to deluxe leather, with or without the textual apparatus.
http://www.amazon.com/UBS-5th-Revised-Greek-Testament/dp/3438051168/ref=sr_1_5?s=books&ie=UTF8&qid=1429710489&sr=1-5&keywords=UBS+reader's+edition
http://www.amazon.com/UBS-Greek-American-Bible-Society/dp/3438051494/ref=sr_1_6?s=books&ie=UTF8&qid=1429710489&sr=1-6&keywords=UBS+reader's+edition
http://www.amazon.com/UBS-Greek-New-Testament-Burgundy/dp/1433530295/ref=sr_1_1?s=books&ie=UTF8&qid=1429710489&sr=1-1&keywords=UBS+reader's+edition
The main plus with these is the font, large and clear and straight and dark. The drawback is that the bindings on these books are notoriously known to fall apart. Also, the UBS usually just gives you a one word gloss targeted to the reading at hand, whereas Zondervan at each point gives you the full range of meanings found in the Greek NT. This is better for vocab retention.
Then, VTR offers a Reader’s edition based on the Majority Text:
http://www.amazon.com/Greek-New-Testament-Beginning-Readers/dp/3941750240/ref=sr_1_1?s=books&ie=UTF8&qid=1429711012&sr=1-1&keywords=Greek+new+testament+for+beginning+readers
The glosses on this one are the most complete, and the font is clear and dark, but a little small. This book is bound well but is a bit big and clunky.
I think I have reviewed most of these books on Amazon. My bottom line recommendation is, see if you can a used copy of Zondervan’s first edition. One gets used to the slanted font. But I’d recommend any of these editions.
You can indeed get a Greek-Latin NT diglot:
http://www.amazon.com/Novum-Testamentum-Graece-Latine-Testament/dp/3438054019/ref=sr_1_1?s=books&ie=UTF8&qid=1429711217&sr=1-1&keywords=Greek+new+testament+greek%2Flatin
but I would recommend this Hexapla, which has the Greek, Latin, Hebrew, French and German and English:
http://www.amazon.com/Parallel-Interlinear-New-Testament-Polyglot/dp/069230214X/ref=sr_1_2?s=books&ie=UTF8&qid=1429711217&sr=1-2&keywords=Greek+new+testament+greek%2Flatin
The Greek font on this is large and clear. I’m using it to learn Hebrew and it’s great.
The best Greek-English diglots are
http://www.amazon.com/New-Testament-Greek-English-Diglot-Translation/dp/3438054205/ref=sr_1_2?s=books&ie=UTF8&qid=1429711437&sr=1-2&keywords=NET+diglot
This has an extra large font and it includes excellent notes on the Greek text underneath, with an English translation on facing pages.
and this one
http://www.amazon.com/Precise-Parallel-New-Testament-International/dp/0195284127/ref=sr_1_1?s=books&ie=UTF8&qid=1429711563&sr=1-1&keywords=precise+parallel+Greek+new+testament
has a tiny font but with six facing English translations.
Reading a Ancient/Modern GNT diglot gives you a sense of what Modern Greek looks like:
http://www.amazon.com/dp/9607847172/ref=pdp_new_dp_review
You are forgiven. Now go and sin and no more. 