Try any 3 element beam with 5/8 wave a few feet above, best all round compromise and most cheap rotators will handle it, i ran a 3 ele and mighty magnum 3 on a 10ft pole to rotator strapped to chimney and 6 ft pole above rotator with beam halfway and magnum above at top, almost no noticeable interaction and could pick off usa at will on either antenna.
3 element beam lacks gain of bigger antenna, but has bigger beamwidth giving you more chance of hitting your desired target even when not on exact bearing, i did general listening on vertical, once i knew where long range paths were set beam on that heading and battered in with ease, a pdl 2 is another fantastic choice if you can source one.
Sirio do the sy-3 at reasonable price but you can get better build quality and optomised versions, but in all honesty for the extra gain or strength probably isn't worth the extra outlay,
you can also mount it on a 20ft 50mm aluminium or steel pole to rotator and 6 foot pole above it, the 6 ft pole i'd go for 10 gauge for 2 antennas, when wind gets so strong its going to snap antennas, not much will stop it, cheaper to replace cheap antennas than dear ones. I might just use a standard 16 gauge 6 ft mast 1.5-2" diameter, as much better/cheaper to replace a broken mast than broken antenna.
hopefully if i can get permission, i plan to do exactly this, with a Hy Gain 533 CB3 beam and CLR2, but if I didn't have them I'd use a Sirio sy-3 and Sirio 827 or tornado 27 (i have that too),
I wouldn't expect to see much if any performance difference from either setup, just Hy gains are slightly stronger, but in winds that break antennas that ain't gonna cut a lot of ice.
And we have no shortage of winds like that, so may even consider a telescoping 10 gauge mast made from 5m sections with 1m overlap to rotator and a 6ft 16 gauge mast that hopefully breaks before antennas on it.
chimney mounting is another option as is T and K brackets with top one mounted just below gutter. I've never found a tower essential for small 11m beams or verticals, as long as you use strong masts with a slightly weaker top section, things should be good, a strong top section with no give puts all windload on antenna/s,
I've seen the outcome too many times, smashed up yagi's and verticals that usually snap within a foot or two from mounting bracket, much cheaper and easier to source a new mast part than antenna part/s.
That way I can drop it in bad weather and use building to shield it as building would be between antenna and prevalent westerly winds we get off Atlantic.
I'm near Glasgow in Scotland and consider the East coast of N.America a rig check, either homebase or mobile, you shouldn't find it hard in the right conditions,
if wanting to know if UK propagation is runing, monitor 27.555 usb or 27.78125 Ch19 ukfm, some high power stations on those frequencies will be first to show, just as we monitor superbowl for early signs of US skip.
