I personally like the latter, but because the Kaiti style is heavier, it will be probably more likely be perceived as different than the Fangsongti style which is not that heavy. Given that you main body font is 宋体 (Songti, the equivalent to a serif font for Latin characters probably), it is a good idea to use another style like 楷体 (Kaiti) or 仿宋体 (Fangsongti).
Of course, it is possible to slant characters, but – as you state – this is not a very professional solution.
Chinese script has no concept of “italics”.
