Anton Duffy, 38, Martin Hughes, 35, Paul Sands, 31, and John Gorman, 57, are alleged to have planned to kill Johnny "Mad Dog" Adair and Sam McCrory.
Mr Duffy and Mr Gorman are also accused of planning to murder former Barlinnie Prison governor Derek McGill.
The four men deny all the charges. Their trial was set for April 2015.
Judge Lord Boyd set the date at the High Court in Glasgow after hearing that the trial is expected to last for 10 weeks.
Three other men - Craig Convery , 37, Gary Convery, 34, and Gordon Brown, 29, - will also go on trial accused of allegations linked to the terror plans.
It is alleged that Mr Duffy, Mr Hughes, Mr Sands and Mr Gorman, along with un-named individuals, plotted to kill Mr Adair and Mr McCrory between August 2010 and October last year.
All four also face another charge of joining others with the "intention of committing acts of terrorism".
This includes claims that contact was made with Republican movements, the Real IRA and the IRA.
The charge alleges there was a plan to identify individuals and premises "to be the target of action" causing serious harm.
Mr Hughes, Mr Sands and Mr Gorman further face a separate charge of intending to assist Mr Duffy in acts of terrorism.
Mr Craig and Gary Convery are accused of directing others to commit serious offences such as drug dealing, possession of firearms and those under the Proceeds of Crime Act.
This includes instructing individuals in the sale and transportation of a number of deadly weapons such as revolver guns and rifles.
Mr Brown is also charged with agreeing with the Converys to help in the "commission of serious organised crime".
One accusation states he met with Mr Duffy and handed money over to him.
The trio are also accused, along with Mr Duffy, of possessing an assault rifle at an address in Paisley, Renfrewshire.
Craig Convery faces a final charge under the Proceeds of Crime Act of having Â£5,660 in money on 12 September last year.
All seven accused deny all the charges against them.
Four men charged with attempting to murder two former leaders of the Ulster Defence Association are to stand trial in Glasgow next year.