quickbooks is good for 0-3 employee based companies. It handles all the accounting and gives you numbers. it is a good software package if you do not want to know the whys and what nots of your businesses financials, and just want to keep the numbers.
peachtree, on the other hand, is an accounting solution. While you would need more accounting knowledge, peachtree is much more flexible as far as accounting goes, and much more powerful. It is meant for more of a 3-50 employee company.
If you are using another program to tie to the accounting program, research what it has to offer. Quickbooks has a fairly good sdk that a lot of software companies have been using, so a lot of programs will import diretly into quickbooks. Peachtree allows com interface and dde to access the data and allows you to input from other programs, or you can manually import using csv format. So if you have a little savvy it's up to you and what you want.
The only other factor you may want to look at is reporting. Peachtree interfaces well with crystal reports, so you can easily create reports to get the information you want.
