I'd pronounce
Viveka VEE-ke-kah, and
Vjekoslava vye-ko-SLAH-vah (At least so it would be pronounced in Russian way). I really like
Vjekoslava, and
Viveka is nice as well :).
I think you should just look at lists for example here, at BtN.
http://www.vestirna.com/www2/_jmena/jmena.php - Czech names
http://www.foreigndocuments.com/russian_names.html - Russian names
http://www.babynology.com/slavic_babynames.html - slavic names in general
http://www.vornamenlexikon.de/ -
German names.