double ring and bash set up

gt si

hi all, just after a bit of advice really, im currently running an xt chainset but want to convert to a double ring and bash guard set up as i dont use the big ring much, what are my options on products to buy to convert , as there are that many on the market, some advice would be really usefull. i have a gt i drive 5 3.0, its a crackin bike, with loads of upgrades, and i love it but feel like it would be much better set up this way, i also want to run a chain device to stop my chain flapping around! cheers chaps and chapess'es