i think with some figuring, you could easily build a budget long travel setup. like build a link that mounts to the swinger and goes down, so the shock actually goes underneath the swinger..like a banshee or trx 250r. probly ony work with a extended swinger. thats my suggestion..cutting the shock mount doesnt sound safe to me....or the lowering link might work good too.
longer front shocks will just make the whole biek ride higher/taller. which means more unstable....idk if you can buy front shocks that are long enough to make it ride right...