[98] Older Gateway 300 power supply

My uncle called me today and said he needs a power supply for his older Gateway 300 computer. He said the power supply in the computer now is a Newton 200watt model 6500125. He doesn't know if its a AT or ATX power supply. Is it possible to just replace this model with any 200 watt power supply? As far as I knew the only difference in power supplies was if they are either AT or ATX. I found one online so far but it seems like a lot of money for a older 200 watt power supply. Does anyone know if this Newton model is AT or ATX?
http://logicalplus.stores.yahoo.net/ga20posuwifo1.html

If it has this sort of mobo connector it is AT:

https://discussions.virtualdr.com/im.../2008/03/1.jpg

If it is this sort then it is ATX:
http://images.tomshardware.com/2005/...x_classic2.jpg

The 20-pin connector shown in the Newton photo is an ATX type. You don't need to get the exact replacement as long as it has the "fan-on" 3-pin connector necessary for older computers OR has the appropriate bypass circuitry to power its own fan. Many newer-type PSUs claim to replace the older ones without having that connector; some don't work as advertised. I've used this one with no problems - it does the job well.

http://www.power-on.com/gateway.html

Seems the oldest had the AT ps.