Just for fun: try Op 10 #11, Op 25 #3, #4 or #9. These are kind of overlooked on the forum (compared to the commonly discussed ones like Op 25 #6, Op 25 #12, etc).
You'll see that even though they can look as straightforward as ever ( A LOT of people on the forum say they are easier etudes), that these have some technical elements someone simply may not have come across. The left hand in Op 25 #4 at the suggested tempo... I'd take Op 10 #1 any day over that.
Also, the website link you posed has some interesting info, but I'm not too sure about calling Op 10 #1 an etude in arpeggios at all... I think 2 minutes of regular 4 octave arpeggios right hand alone (at the 176 tempo) would be more difficult to play than this etude; the hand stays open the entire time, and there aren't any finger cross overs whatsoever in this one. It's more having the hand adapt to broken chord figurations (I'm not too sure what people refer to as an arpeggio anyway... I usually associate it with at least any form of finger crossing over/under, or else it would just appear as a plain broken chord).
Of the etudes you first mentioned, Op 10 #5 would probably be the most straightforward. The note reading is very straightforward (left hand accompaniment has some chromatic stuff, but the right hand notes aren't a problem to decipher like some of the others). You will understand the difficulty after the first few measures. Some of the etudes may seem straightforward until about halfway through when some really awkward passagework comes up. This one generally (obviously there are a few strange measures) stays put technically. It's a great piece for voicing (the left hand has some really interesting stuff you can voice underneath the right hand).
Also, the slow etudes aren't automatically the easiest ones. Chopin is able to create extremely dense textures in Op 10 #3, and if you don't pick out the individual lines, you will not get why this is considered an etude.