Hi Rony,
For a simple home/office setup I don't think you need a server software like hylafax. I have the following setup, using which, you would feel at home if you are looking for functionality like Winfax. All you need is to install efax. efax is a very small and efficient fax sending/receiving program.
For sending fax:
1. Printing Web-Pages/Email : If you are using mozilla sofware for Web and email then printing to fax is pretty simple. In the printer settings (File -> Print -> Properties -> Print Command) give "kprinter". Mozilla will directly send the file to kprinter and kprinter can in turn print to any of the printers that you have set up or directly fax device by selecting "Send to Fax". This in turn starts the KdeprintFax program. The converting of source document into postscript is handled by kprinter. It uses enscript for conversion. But you can change the default settings.
2. Printing Office documents, spreadsheets, etc.: If you are using Koffice, then you don't need to do anything else. If you are using Open Office then run its printer admin program (/path to/openoffice/program/spadmin). Here you can add another printer. It will ask you select a driver. Just select "generic", and then in the next screen it will ask you to "Enter a command line appropriate to this device". There you should write "kprinter". That's it. In fact, on my system, it offers me "kprinter" as a ready-made command option. :-) Now make it your default printer. You're done. In fact, I suggest that you should use this method only (if you are using KDE) for all your printing stuff. kprinter is a very good program (my opinion) and takes care of lot of things. It even works with cups - I haven't had the experience though as I use LPRng.
3. You can use the above steps for most of the Non-KDE programs.
For receiving fax :
1. Install an excellent program called "efax-gtk". Keep it running and configure it to receive your incoming faxes. All the possible receiving options are available. You can keep it in standby (automatic receive) or answer an already received call (manual receive). You can also fax existing postscript files. efax-gtk uses "efax" as its back-end to do the receiving stuff. The best part is that it includes a fixed version of efax alongwith so you don't have to download it seperately. If you have already have installed efax, efax-gtk will install its fixed version as efax-0.9a.
Whether what I have described above is better or hyla-fax is better, I leave it to the user. Since you seem to be interested in offering your clients (who normally are home/office users) and who expect things to be as simple and functional (as a few really good programs in Windows are - yes there are a few), I couldn't resist writing this mail. If you remember I had giving a brief description of setting up your Epson LX-300 printer. I always feel that if Linux is to reach the masses, then it should have those functionality that the masses need. That requires effort, but not impossible to achieve.
Regards, Rajen.