SDHC in Hurricane

I doubt you will find anything for SDHC on this device. Only for Tornado - after a long wait - someone found out that OMAP850 drivers for the Startrk could also be used for the Tornado.
I don't know how the Startrk drivers were created, but for sure there are HTC devices using OMAP 850 which have SDHC support on WM6. So it was sure that the Tornado can support it as well from HW point of view.
If you do not want to create a low level driver for OMAP 750 yourself, you could invest in finding a device with OMAP 750 (like the Hurricane uses) that has WM6 and SDHC support. It is however not likely you find one :-(

If you like your Hurricane - don't worry. You can replace the PBA inside the Hurricane with a Tornado PBA without any other change to the device. They are 1:1 compatible (mechanically: identical size in any regard and electrically: LCD, keyboard, Camera).
So if you find a broken Tornado (no matter how worn or cracked) where the PBA is still alive - get it and give it a new live in your housing of the Hurricane.

There are no Hurricane specific driver threads. It is a re-use of generic WM 6 variant drivers on top of the low-level drivers.

And yes - if you manage to open the case (be careful when opening not to rip away the flex cables for camera and keyboard) then there is no soldering required.
Look up the service manuals for either Tornado or Hurricane (even Typhoon will do) to get an idea which screws to remove and how to remove the antenna cover. Challenge is to swap the LCD if you need to - some delicate handling of the flex connector as well there.

No impossible mission, but you need some mechanical skills and a rainy day without time pressure if you do it the first time.

Depending on your budget the cheapest solution may be to wait for a good opportunity on ebay to buy a used Tornado - they get sold for 20+ euros. If you do not need WLAN, then go for the SPV C600 (France) or the O2 XDA phone - but these are rare species these times.

Finding this on ebay will require a few weeks - so be patient and keep on looking. How much would you want to spend for a Tornado (XDA phone - no WIFI, or the 8310 with Wifi)?

Regarding the drivers: Seems like you did not get the irony in my comments Writing low level drivers is something very special. It is virtually impossible to write a driver on your own - so forget this option!

Did you get it? If you replace the PBA - then you may still have the case of a Hurricane (despite in the US or China the same case carries a Tornado) - but the device is a Tornado then - bye bye Hurricane.
The Tornado was built in two flavours with and without Wifi - more common in Germany was "without" as the O2 XDA phone has no WLAN. The other device is the Qtek 8310 (also in silver as Vodafone VDA 2) which has WLAN. It will only rarely happen that broken devices are sold (people just put them in the waste or return them to the shop for recycling) - but keep on watching.
If you get a fully working Tornado I would not bother to replace the PBA but use it as it is - unless you disassemble it for fun and learning.

...just to close the query: It IS (!) possible to have SDHC in the Hurricane working. read about it in my related kitchen thread (post 4) http://xdaforums.com/showthread.php?t=1553132
Kitchen is not updated yet - but who cares anyway...