The cracks are around the injector bores thus this head was phased out in favor of the smaller bore (for 7mm injectors)
The intake horn from (just about) any application will work as the bolt pattern is the same. This would include OE horns and aftermarket castings. I like to build my own.
The addition of aftermarket horns has been a subject of much debate in terms of performance. I just like the looks of them, compared to the small OE aluminum cast. I seriously doubt my trucks go any faster... ... ... . 500 RWHP doesn't seem to be a problem with the OE design.