from whichの使い方

In cooperation with Reynolds Credit Union, employees may now have money deducted directly from their paychecks and put into a special account.
We have a variety of special accounts from which to choose.

上のfrom whichの文は、
We have a variet of special accounts which you can choose from.
と意味的に同じですか？

だとすると、from whichとなるのは何となく理解できるのですが、
その後whichの後に主語や動詞が来ずにto chooseとなる理由を教えてください。