ERC Floor finish

[Carpenter]

I had a question today about a finish to use on an eastern red cedar floor.  I really didn't have a good answer as I've never finished an eastern red cedar floor.  I build some furniture mostly out of cedar and for the outdoor furniture I've had good results with Helmsman spar urethane.  For the indoor furniture I've been using several coats of a linseed oil turpentine mix followed by several coats of formbys tounge oil also with very good results. 
     I think the spar urethane may be a little soft to use on a floor.  Is there some other sort of a polyurethane with a uv protectant in it?
     I've used the linseed/tounge oil finish on a lot of woodworking projects over the years and I really like it.  I know that it holds up on maple and other woods.  I've used it on cedar and the projects look beautiful when they leave the shop.  But, I've sold everything I've made so I really wonder how it will look in a few years?  So far nobody has brought anything back complaining that the finish has faded, infact I have a lot of repeat customers so, I guess the cedar is holding it's color alright. 
     So, I guess I really have two questions.  What finish to use on an ERC floor and wether or not my linseed/ toung oil finish is adequate for eastern red cedar? 

[zopi]

I would use a hard floor poly...might want to thin the first coat a bit and lay it on kind of heavy...erc is thirsty stuff...then a couple coats on top of that..
Spar varnish would be ok, but it likley would not stand up as well as floor poly.

I have two coats of waterborne floor poly in my workshop, on soft pine, amd it holds up pretty well.