i been getting qoutes and one guy told me i need shortened shocks for the rear if i want to put superlows in or ultra lows is this true????

Yep, its a must for anything lower than 'lows', unless of course you want to destroy your shocks in a few months and bounce all over the road.
At superlow and ultralow levels, the shock plunger is not operating in its correct range and the shock will also bottom out easily.