Since the Home Office have changed the points based system, it has in many ways got harder to satisfy the requirements as they have removed any element of discretion and made the rules absolute so you either meet them or you don't.
If you look into the student visa (Tier 4) requirements, http://www.ukba.homeoffice.gov.uk/studyingintheuk/quickguideforstudent/adultstudents/applyingforanadultstudentvisa/ he will need to accrue 40 points to come to the UK. 30 of these he will get from doing an acceptable course at an appropriate level and the other 10 he will get from having enough money to sustain himself. If he doesn't have a good grasp of English yet, rather than coming on the Tier 4 general, he may be better off coming on a short course for 6 months to study English (student visitor) . This will give him 6 months to improve his English, you will get to spend longer with him to see whether you want to be with him (I assume by CP you meant civil partnership) and then you will be in a better position to then make a longer term application in the future once you both know what you want.
You may struggle to bring him over on on a Tier 2 General visa (work permit) as he will need to get a job first and it doesn't sound like your company would be able to sustain him. Also if he has not finished his degree then it is unlikely that he will satisfy the requirements of Tier 1 (HSMP).
Your only other option is to bring him over as a general visitor so you can see whether you want to be together or not. He will have to demonstrate that he will go back at the end and sometimes the Home Office can be quite particular about this.
It would seem that the Student visitor where his visit will be dual purpose would be the best option if you are not ready for CP yet (or ever).
I hope this answers your question in which case please Accept. If you require any further information, please ask.
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