I'm currently buying a property in the UK with my niece (who is a first time buyer). You have to be the only buyer as well (if I co-purchased, she lost the benefit on the whole property not just her half). So I suspect a company would result in the same loss.
We have had huge difficulties with the fact that I am overseas. Originally, the plan was to co-own and co-mortgage. That didn't work (nobody would give a mortgage to an overseas buyer of my age). Then I offered to just fund my half in cash (that resulted in the loss of the stamp duty benefit and her mortgage provider would not accept that). Then we tried giving her the money and setting up a family trust to get it back if she sold it (that almost worked, but her mortgage provider will only accept if I get back my original stake and not reflect any change in house prices AND we lost the stamp duty benefit???). So now we are on the strategy of me lending her the money and having a second charge on the property AND the trust (privately). So far so good.
Her solicitors are the worst pain in the neck to deal with I have ever come across. So choose your solicitors well and find out how flexible they are (the solicitors basically said they would tell the inland revenue that I was part of the purchase, even though I was not going to be an owner, and niece would lose the stamp duty benefit!). If you get a bunch of assholes like ours, you will have to lie to them too.