Chihiro's are hard to come by these days. I've seen maybe 2 or 3 on ebay in the past, so I think you might just have to buy it off someone else. I've not seen any store that has this system for sale or in stock. Sorry! :smt083
You'll be very hard pressed to get a Chihiro from anywhere, Sega/Namco in Japan ask for all non used Chihiro's to be sold back to them for customer repairs (Microsoft have ceased supporting the Xbox arcade board, so that board is non-repairable).
Also there is different type's of Chihiro, Type 1 and Type 3, Type 1 is the earlier type which used a Naomi type dimm board, Type 3 was an integrated black cube.
Price for Chihiro's these days is around $2000 / ?1000
Outrun 2 SP also will cost you a fortune.. Cheaper to buy a complete machine than software/PCB.
I think I can get some NOS ones, but I think they are Type 1 and will only play Virtua Cop3, HOTD3, CT HR, OR2 and Ghost Squad