Just get a b16a or b18c. Whitch the extra moneyt for a b16b you could throw some mods on a b18c.
b18c Complete change over - 3,149$
b16a Complete change over - 2,250$
b16b Complete Change over - 3,800$
b18c R Complete Change over - 4,950$
There you go. Get the gsr swap then start getting parts for boost.