Mark, as to payment. You're on the right track. An "Order of Payment" is actually far more risky than a "Bank Draft". Each is just a promissory note with nothing to guarantee payment. Yet using the bank draft in the proper fashion allows you to hold the signed lease until actual payment is received. If you're unfamiliar with the process search this site as it has been discussed extensively.
Best bet, do ask them for a cashier's check. However if they refuse, work out a compromise which allows you to withhold the signed lease until payment (cash) is in hand. A bank draft is one option but not the only one.
Bottom line, there is no need for any lawsuits when following the rule; "Until they pay they don't get your lease." Good Luck (and go set a new MT record on your minerals).