I'd like info on the Remington 870 and the Bullpups Unlimited kit for them

[xcutnr1]

I've decided on this setup already. I'm wanting any info on them, as I like to be very familiar with anything before I entrust my life to it. I'm planning to purchase one and find a 20 ga 870 to put in it. Anything to watch out for or look for specifically? What extra add-ons do you recommend and why? Flash suppressor? Tips/tricks for disassembly/cleaning? What choke/shot do you recommend? Anything else I should know? Thanks for any input you might have.