If it was small text edits you could edit it directly in acrobat if you had Acrobat Professional. You go to Tools>Advance editing>text touchup tool. You can then highlight text you want to change and make changes. Sometimes you are have to load the font used in the pdf into you system fonts.
If it a file you want to eventually want to send to a printers then I would definitly recommend using a design house, printers hate getting word files to print.
If there are massive changes you might be better off getting a design house to do them for you, unless you are well used to formatting things in Word. My experience of converting complicated documents from pdf to Word is that things jump around a lot.
As far as convertors - A friend has used before and found it good, but I have never used it myself so don't know much about it.