Smartlist is probably your best option, View>>Smartlist. Here you can search by any number of factors. Expand the Sales Transactions object on the left, click the asterisk, and then click Search. You can select any number of fields, and you can use columns to add fields to your view. Then click save to save a favorite.
If you want to be able to pull up a document in sales transaction entry by customer name, you can do so in the lookup window. Just click the binoculars icon to search by customer name. Or click the down arrow by View on the left hand side (above the list of documents), and choose Custom Sort. Or you can choose to set up an advanced lookup, if you do this Customer Name will be available in the drop down list of sorts in the third column on the right. Advanced Lookups are set up under Tools>>Setup>>Company>>Advanced Lookups.
Take care,
Christina