Oh, thanks for sharing about the installer error, it has been passed to the maker of the application. Unfortunatelly, it seems you will have to do it manually, the xp may be the case. Download the winrar archive from dropbox/mega/moddb, make a folder in mods for d2se and place data + plugy.ini + d2sesetup.ini there. (Located in the archive, mod's name folder, or just extract the very folder there to mods folder,)
Then this should be suitable for you pretty well. Each Act has it's own items to collect, all are meant for somehow empowering you and your party.. Story may be primary, but I believe collectables are not falling behind.