In theory yes he should be able to apply for a B2, however he'll not only have to show that he has strong ties to the UK (a job and property are two big winners) but he'll possibly still be somewhat interrogated for each visit.

I'm unsure if the USCIS have implemented changes proposed in 2002 that would also place possible limit's on any individual length of stay (the length was to be decided upon by the immigration officer at the port of entry) - the default being 30 days with the maximum possible period of 6 months.

US border officers can be somewhat tough to deal with - my ex (A US Citizen born & bred) was once interrogated when we returned back to the US after 9 months in blighty (he was a permanent resident in England) as to why he was coming back to America and why he'd spent so long in the UK!