I generally advise downloading the PDF files available on Saints' Books to your own computer, perhaps to your desktop or a folder on it. They will load faster and flip pages faster, especially in the case of the facsimiles rather than the retyped versions, with those it's much better than reading them on the Internet.
They do not take up any significant hard drive space.
There are fascsimile versions of the first two books of the Catena Aurea as well as the retyped version. Would you be interested in this sort? These are the each page photographed instead of each page retyped version.
Some PDF viewers let you place books in a side by side two page at once mode that can be easier to read.
You can also print out significant portions of some of them if you have a laser printer with enough toner. I'm not sure how fast an ink jet printer would run out of ink on the other hand. Usually you can print much more cost effectively in black and white with a laser printer.
I think some of these writings can be purchased too in print, though I have not looked. Sometimes there are proper editions othertimes there are lower quality but perhaps acceptable facsimile copies people sell of the printed PDFs.
One should prioritize first finding the most literal english translation possible, which I think is currently the original Douai, and reading the Vulgate if you can, or reading the translation side by side with it, as in the end the Latin is going to be the most exact you can find and a good reference for looking up word meanings. Holy Scripture in English and Latin, and a commentary all opened up are a splendid preparation for reading and study. Some of the commentaries have the English translated in them too, and so are more portable. It is also not hard to pick up Latin words, as many English words are derived from them. Some people would not be happy with the old English spelling but you can pick it up pretty quickly if you put in a little effort. There are also modernized spelling versions of the original Douai. There used to be a partially modernized version on a university website but I believe it is gone now.
I am very glad to hear you are so happy with the commentaries! I am as well. They are of a special character.
I think it is not too hard to know the meaning of many of the Latin words below here:
1 In the beginning God created heauen and earth.
In principio creavit Deus cælum et terram.
2 And the earth was voide & vacant, and darkenes was vpon the face of the deapth: and the Spirite of God moued ouer the waters.
Terra autem erat inanis et vacua, et tenebræ erant super faciem abyssi : et spiritus Dei ferebatur super aquas.
3 And God said: Be light made. And light was made.
Dixitque Deus : Fiat lux. Et facta est lux.
4 And God saw the light that it was good: & he divided the light from the darkness.
Et vidit Deus lucem quod esset bona : et divisit lucem a tenebris.
And reading them you learn more about the Church for example 'tenebris' immediately brings to mind 'tenebrae'.