Shortening shocks will give the shock more travel, however, the bumpstops will still be the same distance from touching as they were. On my ae92 I eventually had to replace the bumpstops because they wore quite badly after 2 years, I was running standard shocks. Once they had worn down quite a bit the shock would bottom out...not good.
For long term use I'd go with what the others say & save for some heavy duty shocks. Untill then just keep it bumping off the stops.