In terms of strong unis for history of art, also keep in mind the Courtauld is probably one of the best places for it, possibly stronger in some respects than Oxbridge. Also bear in mind different unis may focus on different periods or regions - for example if you're very interested in non-Western history of art then SOAS may be the best option as this may be less well represented at other unis (they also have a joint course with UCL, or at least used to).
I did a history of art module when I was at SOAS, I really enjoyed it. As above there's a lot of reading, and a lot of writing. Also a lot of looking at things! Don't discount the value in going to look at something in person if available - while not history of art, I had to do a sort of similar-ish assignment in an archaeology module I took last year at my current uni (UCL) focusing on a particular object, and it was only because I happened to visit in the museum that I noticed a really interesting detail which they had some signage in the museum about (but not on the website for the museum) and that became a focal part of what I wrote in my assignment (which got very good marks - I suspect I would've gotten more average marks without having noticed and analysed that detail!).
I think a couple courses might have some slightly more practical conservation oriented/handling sessions but this may vary a lot depending on the uni/course.