http://www.nextag.com/buyer/pro...uct=516372

http://www.calibex.com/Aten_Cat5...bex1z2-htm

These are CAT-5 extenders. A CAT-5 (or 6) extender is the best solution. If you buy good ones, they will work over max. 50m. If you buy the cheapest, you will have trouble with frequently loosing sync due to noise or pulses on the line. Remember that you will get what you pay for. Trying to skimp usually bites you in the tail. (yes, I have a degree of experience with KVM extenders, not altogether good).

http://www.lindy.com/uk/produc.../index.php

This one is almost as cheap as one of your vga chips ;-). Doesn't work over CAT-5, you have to use VGA cable. I think you can bet that this will do saving your VGA cards, but you will probably have a crap picture quality after 33m of cable. VGA just wasn't made for this.

And then your lament about now facing big costs that you will have to make to repair what you have caused yourself in the first place (no, I'm not angry, you should be at yourself)

Sometimes things just aren't cheap or a good idea to begin with. VGA boards are NOT DESIGNED to drive monitors like that, and if it works, you should count yourself very lucky. Unfortunately, as you have found out: it doesn't work. The lesson you should learn from this is that you better make DAMN sure that what you propose to paying customers will work at least reasonnably well. Do not assume it probably will! PLAY IT SAFE. Take a risk sometimes, but what you did was downright careless. You will probably now be obliged to fit extender units at your OWN COST. You should have tested before you sold the system! (if you didn't have the experience from a previous project anyway). I would advise you to take up this habit straight away, the extender business being the first to apply it to. Buy 1, try it thoroughly, and only then install it with the customer.
As you probably know, building a good reputation is a looooong, subtle process, but the first disaster will destroy it overnight. I suggest you save face with your customer as soon as possible, and keep the damage to a minimum. Remember: customers talk to other customers. If you handle this decisively (even though it hurts you financially), it may even help improve your rep.

Success, Mahmood!