check rs25.com for sale too - I've seen a number of pairs of EJ251 heads for sale there recently. Not sure you'll meet your $350 price if they're being shipped, though.
I'm gonna be pulling a engine from a 01 lgt with fresh heads, the block has a hole in it from a rod. Should be about a week till I get the time, and a engine hoist available. Lmk 952-426-8491