It's ''The Bachelor'' -- in breeches! PBS has snagged the rights to a reality show sure to make Mr. Darcy fans swoon. Already a modest hit in England, ''Regency House Party'' (which will air this November) follows 12 modern-day single Brits who must pitch woo a la Jane Austen, flirting and scheming their way into advantageous relationships according to early-19th-century rules. And yes, there's a ''bed checker'' to prevent any 21st-century-type hanky-panky. ''House Party,'' which comes from the folks behind the net's time-traveling ''House'' series (most recent: the 1628-set ''Colonial House''), ''is more fun and frolicky,'' says executive producer Jody Sheff. ''Instead of putting families into dire-straits situations, this is more about 'Can these singles hook up and actually survive in the summer of 1811?''' Call it the summer of very proper love.