That much of a drop is going to be abusive on any shock you use.

A bit of an explanation of suspension travel is in order.

Suspension travel, is essentially the available distance your suspension has to move up or down. Coil over kits or lowering springs naturally reduce suspension travel, because they keep the shock compressed while it is at rest and they don't allow it to fully extend. The shock is designed to offer up a certain amount of damping force over the full length of its stroke and while a reasonable amount of lowering is okay, too much eats up too much travel and the shock can no longer do its job properly.

There is really only one way to maintain proper suspension travel when lowering and it can be accomplished through two methods. The lower shock mount has to be shortened. The full length of the shock is not taken up by the shock absorber itself, so shortening the mount makes the overall length of the shock less, to match the lowering. This can either be accomplished with shortened shocks (i.e. Neuspeed/Koni SP3) or with a full coilover setup that has a threaded lower mount that lets you change the ride height while keeping the overall length of the shock/spring combo the same.

For the amount of lowering you're running, the only way to maintain decent suspension travel is with a full threaded coilover setup as I described above. You can run the Neuspeed/Koni SP3 shocks which will be better than running a stock-length shock, but 2.25" is more of a looks-oriented drop than one which is going to maintain optimum shock performance.