Most brands will make JR boots, the SPK Kaid is good if you have a wider foot. the X3 JR can be good for a narrow foot. Head make some good JR boots. Best bet is try to find a decent shop, no offence to your brother but he does not sound like he has been fitting boots long, and have the boot fitter asses your feet and properly measure you. Getting things like footbeds will help the fit of the boots, getting full custom may be too expensize if your still growing, but some ready made footbeds will be alot better then the standard insole.
Overall though, dont get a adult boot just yet, wait a couple more years, also remeber witha JR boot you will want to get JR bindings, but again these will be cheaper, and will still work on a adult ski if thats what you end up getting. Skis like the Armada Coda could be good, the Salomon Threat or look at some K2's. Afterbangs are pretty heavy so may not be best for you. but try them you might like them