Sorry Guys
I seem to miss the thread somehow and it loked rude that I was not answering questions.
The accessories:
RMR sight - from Hailstormza.com
the others from andean-inc and from Brownells.
Links:
Brownells:
1. Tri-rail accessory mount
http://www.brownells.com/.aspx/sid=53138/pid=27250/Product/SHOTGUN_TRI_RAIL_MOUNT__MAG_TUBE_

2. Saddle mount
http://www.brownells.com/.aspx/sid=395/pid=62/Product/ASM_8_WIN_1300_12_GA__BLACK_AIMTECH

3. Vtac quick adjust sling
http://www.brownells.com/.aspx/sid=49620/pid=1643/Product/V_TAC_WIDE_PADDED_SLING__BLACK

Andean-inc
4. ATI stock
http://andean-inc.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=TAOS&Product_C ode=ATIMRW4100&Category_Code=advanced_technology
5. shotshell holder
http://andean-inc.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=TAOS&Product_C ode=ATISBS4300&Category_Code=advanced_technology

I installed Elzetta torch with mount (from Hailstorm) so the tri-rail is still on the shelf. I intend to get the picantiny-mounted ghost ring and the front fiberoptic sight so I can either use the RMR or the iron sights.
The recoil: the main difference (for better) is that I have a shorter stock so I can control it better. With regulated stock my wife (she's quite small) can also shoot it much better.
Accuracy: I did not have much time to fiddle with the slug load, but I get all shots in 20x15cm plate at 25m. At 50 m the spread is too big with about one in 4 shots getting off the standard impala target. Still need some work on the load
I chronoed the load at 1075fps. (1oz slug)
MJ