Marc Vetri, one of Philly's most honored chefs, is planning to blaze a trail with his second restaurant. Vetri signed a lease Friday for a space at 640 N. Broad St., on the ground floor of a building being converted into about 265 high-end lofts. As housing prices soar in neighboring Center City and Fairmount, luxury developers are looking at untapped neighborhoods nearby. Hence, $2,300-plus-a-month two-bedroom apartments at Broad and Wallce. The project is two blocks north of the School District of Philadelphia's New Headquarters. Vetri says his restaurant, to open around Thanksgiving, will be upper-end casual affair called L'Osteria, a far less pricey affair than Vetri, his Spruce Street eatery, which opened in 1998. L'Osteria will have a wine bar and a wood-burning oven. And, he adds, plenty of parking. It's more accessible than Walnut Street, Vetri says, referring to patrons who routinely get trapped in valet-choked Center City who will instead be able to zip down Broad after dinner. Vetri knows of congestion. Even his reservation book at Vetri (1312 Spruce St.) is full a month in advance.