The Blower Shop did a nice job on my Merc/Weiand 256. They can and will repair it better than new with double row bearings and their better gears.
They are doing all the warranty, and most of the out of warranty repairs on B&M and Weiand (both Holley companies now) superchargers.
The only problem you'll have is the downtime. I took them 6 weeks to do mine in the winter. In peak season????
You can buy the "automotive" version from any Holley dealer for a lot less than the Merc/Weiand version. The only difference is the street version has keyed input shaft, where the Merc has a splined shaft. Of course you can put your snout on the street version. I recently priced one for a friend in your situation, and it was $2250 for the "satin" version and $2350 for polished. Go satin if you want to paint it Merc HP blue.
These prices were for the complete kit including intake manifold, gaskets, belt and fasteners. I'm sure you can buy one without all these "accessories" for less.
Plan C is the Blower Shop billet 250 blower. It is sweet, but expensive.
Good luck and let us know how it turns out.