Manual Trans Upgrade (non-turbo)?

Hey all.

I'm new here, though I've been a lurker ever since I bought the car. I have a '95 Stealth with the SOHC engine. I love the car. It's a beautifully designed car and a joy to drive just about anywhere, imo. But I have one major problem with it - the 5 speed manual trans is not great. I shift into 5th gear at around 50 mph aaand that's it. The speed limit on the interstate I travel daily is 70. I've regularly got cruise set to ~77ish while my tachometer tells me I'm running ~3500rpms the whole time. That's not good for mpg or the engine... As made apparent by the head gasket I recently blew and the rising gas prices.

First off, is this normal? I also drive an '02 Bonneville SSEi as my main commuter and it seems to chill around ~2300-2700rpm at interstate speeds with the cruise set. It's an automatic, though. My Stealth is my first manual vehicle and I guess I don't really know what's normal for them... But 3500+rpm cruising doesn't seem right to me.

Either way, I really wouldn't mind an extra shift now and then and was wondering if there's a decent upgrade option to the stock manual tranny for the Stealth? From what I've read, the Getrags from the turbo models have their own issues and they aren't terribly cheap anymore, nor are they exactly "plug and play" with the SOHC engines. I do intend eventually to replace said head gasket and upgrade the headers while I'm back there. A transmission that can handle a little extra torque over stock now and then wouldn't go amiss, and I've even given some thought to a custom supercharger setup as I've got plenty of room under the hood and I really appreciate that extra off-the-line power I get from the Bonnie when I want it.

Thoughts? I'm open-minded toward a fair amount of custom fab work as I have the tools and workspace to do it, but I'm not super confident in modifying a drive-train and thus would also appreciate as little extra effort as possible.. xD

The only transmission "upgrade" is a Getrag. You can bring your 5th gear revs down a little by putting a DSM 5th gear gearset in your car. There's also an even taller gearset from an early Evo, but its not really available unless you find one used.