I also work with the HVX, and have been happy with it.
I use AVID Media Composer and FCP – both of which handle P2 just fine.
For GFX, I think it is probably a toss up – though I tend to lean towards the AVID. One thing that will allow you to do what you want with Alpha’s and real time is to have a good Sata raid (4 way strip will work best) – this applies to HD, for SD and mutiple channels the Sata Raid will scream!
Lawrence S. Young
Best Shot Productions
Maine•New York•Colombia
421 Paradise Road
PO Box 110
Bethel, ME 04217
Home: 207-824-3119
Cell: 508-494-3111
Email: lsyoung@megalink.net
Adjunct Professor New Media, University of Maine at Orono
Link to work: https://my.media-match.com/lawrence.young1