Are you wanting to re-cover the whole dash, or just a top cover like those aftermarket ones?
Covering a dash in suede would be possible, but it'd also be a big bunch o'work! Mostly due to getting it all the parts to fit & work properly with the added bulk that the suede would add. Specifically around the gauge pod, the radio opening + those vents & the like.
It wouldn't be able to be done in a single piece. That stuff isn't able to be molded, so the cover would have to be made in sections & then sewn together so that it would fit all those contours.
I've done many dashes for other vehicles, but usually in collector or specialty vehicles where their value justifies the cost of the job. As there is no pattern for a job such as this, each piece has to be fitted individually, then sewn together in order to for the combination of pieces to fit with each other & the dash. Last one I did was one for a DeTomaso Pantera. A lot fewer contours than a GMT400 dash, but even still, it required 17 individual pieces of leather & by the time my labor was calculated in, the customer had a bill for $1000.00. That included the leather $$$.
Additionally, the dash is an area that's subject to some extremes. Not sure how that suede would react to that constant exposure to UV-rays, the heat from the sun in the summer or the cold in the winter. The black suede that I've seen that is any where kinda of old usually has turned to a dark purple or dark brown.
In other words, pretty intensive, intricate work, labor-wise, with a material that's questionable in it's endurance.
If I was to attempt something like this, I'd be more inclined to use a Marine Grade vinyl, (mold & mildew resistant, U.V. stabilized) or (feeling spendy?) a similarily treated leather.
Here's an alternative to sanding/painting or recovering in suede/vinyl/leather.
http://www.gmt400.com/threads/how-to-dye-plastic-vinyl-leather-carpets.21865/
