I use KOReader, which currently doesn't do "collections", but you might look into the collection management that calibre can provide.
KOReader now has its own forum. Tshering's Kobo Start Menu (KSM8) is the best way to launch KOReader and has a number of features that the slightly technical of us can make good use of, but there are other ways to launch KOReader, as well.
KSM, as the name implies presents menus of scripts that when selected can do many things, of primary concern here would be its ability to select and launch the stock software (Nickel) or KOReader or the Vlasovsoft Launcher with Coolreader.
The KSM8 thread. The first post provides a lot of information but the actual installation is relatively straight forward.
Here is an install guide, that might help. It won't hurt to install just the additional readers you want, or install them all, there is no performance penalty to having them all.
Memory Upgrade guide. This will probably effect the waterproofing of your H2O, (the neoprene glue used to repair wetsuits has been suggested as a way to restore the seal.).
Luck;
Ken