Those by St Theophylact of Ohrid are what I would recommend for catechumens both for it's relative brevity as you have said and also because he clearly reflects the writings of the early fathers (main St John Chrysostom) in a way which is easier to understand, he also gives to interpretations when there is more than one way of reading a passage of the scriptures. However as the translation is a modern one by Chrysostom press it is not available online except for extracts if you can I would recommend buying some of his commentaries, should you choice to then I would say to get the hardback as they are very good quality whereas the paperback has a tendency for its cover to wear very easily. From your profile I see you are in Australia so I can't recommend any suppliers though I'm sure there are some.
As to other fathers the commentary of St Cyril of Alexandria on the Gospels of John and Luke may be found on here http://www.tertullia...thers/index.htm though these are not by any means as easily to grasp as those of St Theophylact, his commentary on Luke still might be worth reading though even if you have some questions after reading it, his commentary on John on the other-hand is quite complex dealing mainly with teaching the Orthodox faith of Christ against Nestorius.
Fathers fairly easy to read but who do not always give the consensus patrum in the same way as St Theophylact are,
St Bede the Venerable - homilies on the Gospels (feast-days), Acts of the Apostles, Catholic Epistles - available as books
St Gregory the Great - homilies on the Gospels (feast-days) - available as a book in two volumes
St Augustine of Hippo - Commentary on the Psalms - Available on-line on the CCEL website.
They should be available in Roman Catholic bookstores should you not find an Orthodox one nearby
Another source is the Orthodox New Testament by Holy Apostles Convent vol I&II which has fairly extensive footnotes of patristic quotation.
The link you provided looks like a very good site, sadly I don't know of anything similar in English, though scripture wise to accompany careful studying I would recommend Michael Asser's very well done Old Testament the old edition of which is available online here http://orthodoxengland.org.uk/zot.htm (I feel I must say I would not recommend using the rest of the Orthodox England website) an alternative in modern English is N.E.T.S. (http://ccat.sas.upen...u/nets/edition/) very well done scholarly translation but very literal and not as good from an Orthodox perspective, for the New Testament the best online I would say would be Young's literal translation (http://www.ccel.org/ccel/bible/ylt) as it best follows the Greek in most places, though is harder to read then may due to its literalness.
I hope some of that is of some help.
In the Risen Christ.
Edited by Daniel R., 25 May 2014 - 04:18 PM.