Can't decide! I suppose it depends on the partner. For Willem I'd probably play someone like Kelsey Grammer or Jeremy Irons. For Robert I love the idea that Kim Coates and Tom Savini look like brothers, if you were open to incest. Otherwise maybe someone like Tommy Chong. For Patrick I'd likely match him with someone closer to his age, in the 70-90 range.
At the risk of barraging you with faces, here's my list in case you see any potential pairings jump out at you:
sam neill, rip torn, john kapelos, john c. mcginley, mark hamill, john cleese, michael palin, stephen king, jeff fahey, hugh hefner, steve martin, michael douglas, iain glen, jeremy irons, donald sutherland, russell crowe, michael rooker, bill nighy, billy connolly, charles dance, kurt russell, sam elliott, john noble, hayao miyazaki, kevin spacey, brendan gleeson, brad dourif, ed o'neill, harrison ford, christopher lloyd, sean pertwee, clint eastwood, morgan freeman, john goodman, sam waterston, malcolm mcdowell, bruce campbell, andy garcia, viggo mortensen, bryan cranston, jk simmons, jeff goldblum, peter gallagher, michael harney, brian cox, lou ferrigno, eric roberts, danny trejo, tommy chong, edward james olmos, sean connery, james lipton, dick van dyke, ed asner