I only ever use Futaba radio gear, now and 20 years ago when I was last into RC. Never had a problem with it, and hopefully never will... all new Futaba RX come with BEC circuitry, so whatever ESC you use, whether it has an additional 2-wire cable for a separate 6v output or not, it will work with any Futaba RX. I use the R162JE 27MHz AM RX. Basic I know but going my the K-I-S-S rule, it's perfect for my needs...

Plus, I've never been aware of any compatibility issues between Futaba and Tamiya equipment.

Finally, if the guy in the shop doesn't know his stuff well enough to sell you the correct gear, name and shame bro, so that others don't make the same mistake!! Personally, I do al the necessary research beforehand, know exactly what I want and/or need for a particular project, then shop around, almost exclusively (but not entirely) on eBay. Most suppliers are based in HK or the US, and ship internationally at reasonable prices. And looking at what most UK-based hobby shops charge, you're bound to save money...