I have 272 8.7mm custom ground wade cams, and i have gotten away so far without flicking a shim out.

Theorist, shimless buckets are the best option, as shim under buckets can still come out of place with valve float, wrong shimming, or a lot of time on the rev limiter.

The pain is reshimming = new buckets.

I was looking at the specs of similar engines to the 4age and many have 10-11mm lift in standard trim. Even with durations similar to stock 4age. Apart from the shim arrangement I don't know why the 4age has such comparatively short lift. Bigger lift and shorter duration should be a nice combination of power and drivability.

The reason you need a bit of duration with big lift (apart from power, and holding the valve open longer to try and get more air/fuel in) is the ramp rate on the cam. If you for example had a 230 degree cam with 11mm of lift, you would have a hard time controlling the valve spring, needing a massive seat pressure, and with that, you are going to have a lot of load placed on the timing belt, as you are trying to open the valve very quickly. You would end up with issues of the belt skipping on the crank gear, or stripping/snapping the belt.

There are a range of factors that affect ramp angle and asymmetric profiles can run shallower open than close. Time at maximum lift also affects ramp angle. Granted 11mm, 230 degree is probably not going to fly but Toda do a 10.3mm 264 degree that I would like to have a shot at. Be interesting to compare that with a shorter lift longer duration
P

This is true. But also bear in mind valve diameter vs lift ratio. A 4age has 29.5mm intake valve. Usually 25% is a good standard ratio, 25-30% is performance rated, 30% is usually only good on race motors, and by the time you reach 50% it is at it terminal flow. A 10.3mm lift cam with standard valves will not be as streetable as you think.

even if you can source a set of smallport na pistons to chuck in it.  made a noticeable difference in my last bigport na aw. bought a 2nd hand set cheap from the forums.  

oh, and if budget stretches, a light weight flywheel. :)
 

Consider the MS DIYPNP, it's a bit cheaper, a little more flexible and has a few extra features onboard. Requires a couple of hours to assemble, but it's all simple through hole components and jumpers.
http://www.diyautotune.com/diypnp/

Hmm yeah that is a fair bit cheaper actually, almost half price. How tricky is it to assemble? Any fine soldering required? I'm no soldering expert but I'm good with Lego and Ikea. ;)

Why not go GM Delco.  Cheap, bulletproof, reliable and no soldering.