Best Store Bought Ground Glass?

[dmiller]

I'm new here.
I don't even have my DVX100a yet (UPS says delivery on Tuesday!!!!).
I've checked the boards thoroughly, but have yet to find a comprehensive thread on it yet (if there is one just lock this up and send me to that one), but what's the best ground glass piece to buy outright from a retail shop?

I've seen many people's 35mm adapters and I've been very impressed with what I've seen, but I'm not sure who's grinding their own glass or not.

I've seen store sold units here:

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1935&srtitem_price=D

http://www.thorlabs.com/NewGroupPage9.cfm?Guide=123&Category_ID=185&ObjectGroup_ID=1132&Visual_ID=546

http://www.redrockmicro.com/p_guide.htm

and one other place I can't find my link to.
I suppose my question is:

Has anyone found the best store-bought ground glass?

Also, I've got an old Konica 50mm 1.7f lens, can anyone point me to a lens mount/adapter to start making my DIY 35mm adapter?
Thanks in advance guys . . .