Online 4.0 and ODBC

Our company has been using an application written in Informix Online version 4.0 running on an HP 9000. We have written numerous 4GL and ACE programs to satisfy one-off user requests for reports that are not in the system we bought. The problem is, once you start doing this it never stops. These reports are usually kicked off via a cron or a user logging in and running them. I really would like to see the whole thing put to bed by using a client server ODBC approach. Everyone in the company has access to Microsoft Windows in a Novell Lan environment. We also do a considerable amount of TCP/IP and FTP communications using Reflection. My question is Do we need to upgrade to Version 5.0 of Informix to use ODBC? If so, what is the ballpark price ? Also, what is the most preferred way of using ODBC from a PC based windows machine? I've seen some mention in this newsgroup of Visionware etc. Thanks for any responses .