Look here:  
https://www.multiecuscan.net/SupportedVehiclesList.aspx
 
For the 1.3 Multijet for Service Reset no additional adapters are required.  Just a genuine (not Chinese rubbish) ELM Interface.  I prefer OBDLINK SX interface.  If you want to cover all systems then A5 and A6 are also required.
 
What year is your 500X 1.3 Multijet?   I doubt it has an SGW installed, but even if it does then you can get a bypass cable.
 
Personally I recommend 
Gendan for 
MES, cables and other diagnostic kit.  The other UK approved distributor is 
BMDiag. Both are authorised/recommended distributors. Others have bought off eBay and other places with no problems but it can be a lottery.