In the meantime, although I am leaning toward the above two LEDís, I would be interested in your offer, @Greggz
(and other T5 users), to PM me about your recommendations for T5 bulbs, reflectors and bulb arrangements.
Keep this thread going!
Here's the thing. T5HO bulbs come in a variety of colors, and a variety of PAR intensities.
So the tricky part is finding the combination that provides you the PAR and color you are looking for. As to PAR, a four bulb set up could provide anywhere from medium to VERY high light, depending on the bulbs and distance from the substrate.
With a typical 4 bulb set up, a good combination might be a good red and blue bulb (Powerveg 420,633,660), combined with a daylight and flora bulb. In general, most heavily colored bulbs are lower PAR, so you can mix in some high PAR bulbs like Giesemann Super Flora or Tropic to get the PAR up.
But really, it's a matter of personal taste, and what looks the best to your eye.
A little while back I tested and posted pics of a variety of combinations (link below). As you will see, the bulb combination can make the same tank look quite different, not to mention the effect on PAR.
FWIW, my current mix is the following, which creates about 135 PAR at the substrate. I can change the PAR quite a bit by just changing out one or two bulbs, and raising or lowering the fixture just a bit.
Giesemann Super Flora
Giesemann Super Purple