Digital BW, The Print

My local Sams has dropped the price of the HP 8750xi down to $430.00.
 
I have been saving up money to purchase an Epson 2400; however, at 
$430.00 I am very tempted to purchase the 8750.  
 
The printer uses three tri color cartridges:  
  Cart 1:  Magenta, Cyan, and Yellow
  Cart 2:  Photo Blue Cartridge with light Cyan, BLUE, and light 
Magenta
  Cart 3:  Photo Black Cartridge with three shades of black
 
My biggest concerns are the use of multi color ink cartridges 
instead of single color cartridges and the apparent lack of 3rd 
party RIP support for HP printers in general.

Can you print on the nicer photo rag papers with this printer?
 
Would any of you be so kind as to offer you thoughts on the 8750 in 
general and specifically B&W printing with it?
 
Thanks!!!