I would suggest Tashia.
There are people that didn't like the Imoen's romance out there, and even if I'm not one of them, I wouldn't suggest it to everybody.
I never tried Nalia's romance, but afaIk it proved so good, satisfying and rewarding that Jason Compton (the author of Kelsey) felt the need to write another
(which is still work in progress).
Otho,I still have to hear about people who tried Tashia and didn't like it: so my suggestion is, go for her!