Eagl,
It sounds like what you want is some sort of device that you can remove from the box, plug into your network, and with less than 15 minutes of configuring or effort, will be significantly better than an off-the-shelf linksys router, BUT you don't want to be bothered with a "custom Linux firmware" for a router.
I'm afraid I know of no such device.
First, it sounds like your current strategy and configuration of your linksys router is excellent. Unless you are aware of some problem with your setup, I would suggest leaving it alone.
But suppose you really want to tinker with things. Next step is a consumer-grade router that supports one of the Linux-based firmwares you were badmouthing, such as DD-WRT. I really like DD-WRT, use it at my place, and have it installed with some clients too. Installing it is really no different than updating the firmware with something from Linksys: you download the firmware file, log into the linksys router and go to the firmware update screen, browse to the new firmware, and click "Update." Within 60 seconds the DD-WRT firmware file uploads to the router, gets read into the chips, and then the router reboots. Goto 192.168.1.1 (or whatever) with your web browser, and start using the new GUI to configure things.
Not only do you get TONS more options, but since it is open-source, there are lots of eyeballs looking at the code and fixing things as they are found. DD-WRT recently found a serious security flaw, (the first major one in several years), but a workaround fix was immediately posted and a new firmware available in 1 or 2 days. Linksys would never release a replacement firmware that quickly, let alone announce there was a problem at all, let alone even finding the problem quickly. Do you really think there's someone at Linksys checking old firmwares for old devices for security flaws?
Next step up are "pro-sumer" routers called Unified Threat Management (UTM) devices from companies like SonicWall. They run between $200 and $1000 and claim to be able to scan all packets for malware and viruses before your PCs even see them. I reviewed 4 of them last year and found them all to, in a word, suck. They are fine routers and firewalls, but their antimalware definitions were minuscule and let most of my test malware zoo through easily. As firewalls they had less options than DD-WRT (though better content filtering for childproofing your connection), but they were easy to configure and most had wireless built in too.
Next step up is a standalone PC with two network cards and a Linux distro acting as a firewall. The easiest ones to use are dedicated to this job, like ClarkConnect (
http://www.clarkconnect.com/index.php), which have lots more features than a router but are only slightly more complicated to configure. Or install a standard distro like Ubuntu and roll your own firewall from scratch, though this is really more like a new hobby than you probably want.
I've gone the latter route too, and it was enjoyable to tinker with things but annoying to have a large computer constantly running, making noise, consuming 100 watts (versus 5 watts for a linksys router), regularly backing it up, replacing failed components, and then having a separate wireless access point for my notebooks (the linksys has wireless built-in, recall).
I think DD-WRT (or one of its cousins) is probably the best middle ground for what you want.
-Llama
