I purchased and installed two 90lb units (from
McMasterCarr ( # 9416 K174 @ www.mcmaster.com ).  
The struts I received were the suspa brand and they cost me
$12 /ea not including end fittings.

They fit great ( the old lancair ones needed to be compressed
one inch to get them on my canopy, while I was able to size
these to within an 1/8" of my canopy's full open position ),
hence easy to install. The new struts bottom out with the
canopy fully open which the old ones did not.

I really like the metal end fittings ( with mcmaster carr you
buy the fittings separate from the strut itself, they have
plastic, steel or stainless).  I used Stainless fittings at
one end since they 1/2" longer and that makes them fit perfectly
to my canopy size.

With only one new strut and one old strut (55lb) its still a
bit weak.  With both new struts its a bit agresssive.   If I
were to do it again I would probably go with 80lb struts.

Only time will tell if these hold up better then the lancair
ones, but they are a lot easier to replace in any case.

Thanks to all that suggested mcmaster for gas struts.

Ken