If your Linksys router has Alchemy loaded on it, clearly it's a WRT54G/GS v4 or lower. I suggest switching it over to
DD-WRT. While I believe Alchemy supports it too, DD-WRT lets you boost the router's Wifi signal. The WRT54G also has removaable antennas. If you want to tuck the router away (out of sight), connecting externally mounted antennas will do wonders for your signal. The external antennas can be mounted up high UNOBSTRUCTED but out of the way.
As for a Giganet router, do you mean a 108mpbs+ on the wifi side? If so, DD-WRT is compatible w/ other routers too (i.e. other than just Linksys), some of which may be Giganet. Check out the DD-WRT home page for a list of routers.
If you're wanting the router to have Gigabit ETHERNET ports, that's not going to benefit you that much. You anyway said you already have a Gigabit SWITCH. If so, connect all of your Gigabit devices to the switch. Internally they'll communicate w/ one another at Gigabit speeds. Externally to the internet, the router's 100mb ports won't slow down connectivity even at FiOS speeds since 100mpbs is faster than that.

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