I know that RSorder is a great OSRS Gold shop.
When my friends suggest RSorder to Buy RS 2007 Gold by mobile, i have a good try. Then, i buy gold & firecape on it, so smooth & safe. But sometimes, delivery not fast, you need contact them on live chat, dont worry, 100% legit and great service.
Most of the time, their delivery is really so fast.
By the way, you can read their reviews, maybe help you.
Good luck~