I know pre-marital sex is haram, but I wanted to know if it’s haram to ask Allah for a type of wife that fits the criteria I’m attracted to, specifically when it comes to sex?
First of all when you make du'a you are free to express what ever you wish or have in mind. As du'a and prayer are opportunities to communicate with your Creator.
Therefore you may specify your wish on whom you'd like to marry and there's nothing wrong with that.
However it is better not to be too specific and to leave things to Allah and show your reliance to Him:
There is nothing wrong with a man asking Allah to make it easy for him to marry a particular woman, and there is nothing wrong with a woman asking Allah to make it easy for her to marry a particular man. If a Muslim man or woman offers supplication in general terms without specifying anything, and delegates the matter of choosing the best to his Lord, such as a man saying “O Allah, make it easy for me to marry a righteous wife”, or a woman saying “O Allah, make it easy for me to marry a righteous husband”– if he or she does that, that is preferable, because it is complete reliance upon Allah and delegating one’s affairs to Him.
(Source Islamqa fatwa #219260)
This is better because it was the sunnah of our prophet ():
The Messenger of Allah (ﷺ) liked comprehensive supplication and abandoned other kinds.
(Sunan abi Dawod)
Our prophets sunnah -for example in istikharah- also show us that it is better if one specifies to ask Allah what is the good or best choice:
Ibn al-Jawzi (may Allah have mercy on him) said in Sayd al-Khaatir (p. 352): Beware of asking for something without connecting the asking to what is good, for perhaps attaining what one is seeking of worldly matters may be a cause that leads to one’s doom. End quote. (Source: Same fatwa as above)
Why is better not to specify or to ask Allah the good in a matter is simple, because if your du'a wasn't answered or the answer was delayed some people may get down or maybe even lose their faith.
Further you should know that in Islam the better choices for a wife are quoted in
The Prophet (ﷺ) said, "A woman is married for four things, i.e., her wealth, her family status, her beauty and her religion. So you should marry the religious woman (otherwise) you will be a losers.
(Sahih al-Bukhari, Sahih Muslim, Sunan an-Nasa-i, Sunan abi Dawod, Sunan ibn Majah and Jami' at-Tirmidhi)
And this should be the best choice.