WOOHOO an eel lover..
First of all ribbon eels are a no no IMO
. They are really hard to get to eat..due to their size, and are very fragile. Also the only in that i have seen that their fins seem to rot real easily unless water parameters are "PERFECT"
That leaves you with SFE and ZE
Snowflake vs Zebra
They pretty much eat the same, this can be prawns, shellfish, scallops. I feed mine by hand but some people would rather use a feeding stick or tongs.
Size: Snowflakes grow to about 24 inches whilst the zebra about double that at 48 inches (SFE - 2ft max, ZE - 4ft max)
Tanks: A minimum 50gal for the snowflake and 100 for the zebra..
(yes if u see my profile my zebra is in a 40.. im upgrading to a new 100gal for him
Hardiness: Well lets talk about the ICH factor; their slimy mucus film protects them from the parasite so they are pretty hardy, but that doesnt mean they are invincible.
Eels in general produce alot of waste so a skimmer is needed, and 20-30% water changes at least twice a month if not more..
If you are anyway in the Sydney region your more then welcome to see my eels, i have a snowflake and zebra (20inch SFE and 36inch Zebra)
Hope we are some sort of help!!