I've listened to your album. What a treat! Very diverse. My favorites are Miami Nights, Infamy H.Q., Composing Stanley and The Brightest Light.
As for Hitman related stuff, these tracks are what defines the sound for me, may differ to others of course.
Hong Kong Underground is my go to hitman tune.
Streets Of Hong Kong is the light version. Great atmosphere. Try listening with headphones to get that binaural audio effect from the chatter/street samples. Also the build up to the ending melody is just beautiful.
Winter Nights is Jesper Kyd's most chill tune and it has an insanely "cold" atmosphere.
47 Detected is the high point of drums and percussion.
The Hitman 2 Main Title is one of my favorite orchestrial songs. It's doable with software but it won't sound as good obviously. The choir plays a big part in the epic factor.
47 Makes A Decision blew me away as a child. Still does. The main hook is just too damn good.
This one shows that he had clear intention of capturing the feel of the location in which the song would play. Great melodies.
My advice is to go for classical/traditional instruments. Then twist it with distorted percussion and heavy drums. If you use synths, make them as less "electronic" as possible. It all depends on what kind of Kyd you wanna capture really. Also try to do location specific stuff. Look up ethnical or asian scales. These kind of things does wonders to achieve interesting soundscapes. These are just my own guidelines really.
Bonus! Here's some synthwave Blood Money for you!
And the Blood Money version for comparison.