Well I've finally gotten the shits with the official tiny PS3 controller and its crappy convex sticks and decided I need something less crap. I was hoping someone here could recommend a decent 3rd party controller (sadly I suspect that may be a contradiction in terms) that fulfils the following requirements:

Xbox style stick layout
Xbox style size
Triggers (or the ability to mount those trigger addons)
Sixaxis support

Wireless would be ideal but it's something I can live without it it has the rest of it.

Nah, apart from lacking the cable I'd need, the lack of sixaxis support would make playing heavy rain next to impossible

You can do it yourself.

Still would lack sixaxis, wouldn't it?

Then get version 2.

How does it implement sixaxis support if the xbox controller doesn't have the hardware to send the signal to the converter?

According to one of the reviews, it has a switch that gives one of the analog sticks sixaxis functionality.
Seems cumbersome. And for Heavy Rain, as was mentioned as the reason why sixaxis was needed, it's probably not good enough.

Yea I saw that while reading the reviews. It would seem the best choice really is to mod the PS3 controller into an Xbox controller case. I wonder if there's any shops out there that sell them pre-modded. :) (The controller is one of the primary reasons I do most of my console gaming on the Xbox rather than the PS3)