I don't understand how you would 'outgrow' a linksys WRT54G in your situation (2-3). If you have CONSTANT crashes, you either have:
a) bad hardware
b) bad configuration for your needs (standard linksys sw? try another firmware flavor)
c) router not configured to limit - uncontrolled people bittorrenting (ton of open sockets) the crap out of the router (which is known to lock up almost all home/small biz routers due to ultra high throughput without config changes).
I have run the Linksys WRT54G with 29 people (small office env), I used OpenWRT on it successfully and have had no problems, it was stable as a rock, complete with full QOS funcationality and a 10mbit inbound/1.5mbit outbound connection.
The WRT54G's only limitations IMHO is 100mbit if you want 1GB+ pay more. If you are fine with 100mb (for internet access!) then WRT54G is perfect.
Myself I ran the WRT54G as the gateway & internet traffic QOSing. With 2 16x1GB switches for network (LAN) traffic. I just had one of the 16xers plug into the router for outgoing/incoming internet traffic. That way nobody was limited by 100mbits until they came off the LAN.
Just some food for thought, don't dismiss the Linksys WRT54G, its a great little router, thats why there is such large community support for it.