I've been enjoying reading a few of the harlequin series, I'm having a difficult time finding an english version of Doctor, Koi no Shinsatsu o and Ikoku ni Musubu Koi and was wondering if such was available on the market.

Thank you.

High above the tree tops.

What exactly are you asking for?

A just ruler amongst tyrants

If you are asking if they are licensed and if you can buy them in English, then, no. The status of both of them are:
"Licensed (in English)
No"

So I think none of them are avaible in English for you to buy (if that is what you asking for).