Breareos

I've done a bit of research into dashes because eventually my car will be faster than my speedo can read, and for track days I'd like to be able to see how fast I'm going instead of seeing my needle spin past 180km/h. That idea annoys me...

Racepak Data Systems - Professional Motorsports Data Acquisition Systems

I was looking into possibly getting a Racepak UDX Street dash as I would like to retain the street legality of my car by retaining my turn signals, odo, and high beam indicator. It's fully configurable, so for instance if I needed to increase the tach bar sweep because the engine can hit a higher limit after new mods, it's merely a simple reprogram. Plus, it can display 4 readouts (well 3 since speed would most definitely be taking up the centre readout for my config) which is good because I want to be able to monitor oil/water temp (*C), Oil pressure (kPa), and boost (KG/cm2) and this would eliminate the need for several individual gauges to montior the function.
Yes, I have looked into Stack, and no, I don't want it. I personally think it looks ghetto and I don't like the layout.

However...

It would be cool if I could retain the OE dash if I could simply recalibrate the speedo sensor for higher speed to match what my engine could output, and then change the gauge face so it had a higher end speed (let's say from 180km max readout to 300km). The thing with that though is I don't know how much that would cost and I wouldn't know where the hell I'd find a new dash face (or even where I could get one produced). If I were able to do this, those additional vitals I would like to monitor could be done by a Greddy Multi D/A gauge, as from what I've seen, it can function as a 3-in-1 gauge.

GReddy

The goal with either solution is that I want to keep aftermarket gauges to a minimum.
The vehicle is mostly a street car, with occaisional track time. Which setup would be more effective for me, but most importantly, the most cost efficient?