If the boots are cracked, there is a btter than even chance that the inner tie rod ends are rusted and deteriorating and there may be damage to the rack seals that will result in leakage soon. The cost of the boots is rather high, so you should inspect all carefully. If either inner tie rods show signs of wear, OR rack shows signs of leakage, you will be better off to install a rebuilt rack which should come with new boots AND tie rods. You will likely still have to get new tie rod outer ends. Installation is straightforward, though a little messy. Rebuilt racks are ~ $230-280.

Be sure to have a belly pan (aka splash guard, aka curb feeler) installed - without it, the boots are exposed to road debris which can damage them - and the boots are more expensive than the plastic belly pan.