The handlebars will be a little crowded feeling with the brake levers and shift mechanisms
??? couldn't you say run one off these? Bicycle Shifter Brake Lever Combo SET, Mountain Bike
[img[
https://i.ebayimg.com/images/g/RZkAAOSwTDhiU67X/s-l1600.jpg[/img]
or grip shifters and brake levers.
or just extend the bars longer. to get more room.
6061 Aluminum extensions, custom sizing available, will come sized @ .740 ID for standard cromo BMX bars unless you specify otherwise. Two styles available:
REMOVABLE design available for lengths UP TO 1.25" per side. Can be transplanted to your new bike if you desire. 1/2" 3/4" 1" shown: