Any phone plan should work with myCRMSIM.
Since you will only be using SMS choose the cheapest plan you can with unlimited SMS and do not worry about data usage and calls.
In most countries you can get a monthly plan for around $10 per month with unlimited SMS.
If sending and receiving SMS overseas is important to you we would recommend that you choose a SIM plan with a direct telco rather than a reseller since reseller accounts seem to have more restrictions with overseas SMS.
As myCRMSIM has users in many different countries across the globe we have put together a shared resource that can be added to for SIM plans that are recommended to use by our users and also ones to avoid.
Please verify any information before making a purchasing decision as this information is crowd sourced and could be subject to change at any time.