I would go for a Bell 206B. It has almost total acceptance as a charter or training machine. If it is used for training, it is relatively benign when compared with any Robinson product, so less chance of damage.
Parts are easily available and as has been said above, just about anybody can operate it or maintain it which gives you the maximum choice when trying to leaseback. Mkae sure that you check the values carefully and try to bargain hard, try and build in a little depreaciation to protect your resale value.
Interestingly, if you study the values of used 206s in the past, many of them have actually increased in value although with some of the newer EC 120s coming into the market, I would not be able to assure you that this will continue.
LE