Yup, those AP Valves SMBci's are pretty common. They are quite big when packed up and consequently tricky to stow. The Co2 Cartridge with oral inflate bag looks about right - company called Aqua Elevation make one in the UK - comes 1.5 or 2m and in red and it packs up very neatly. Halcyon do an oral inflate only too, but it's pricey.
I have 2 Halcyon markers. "Pricey" may be an understatement, LOL.