The radials may help, and as SpaceMann points out, you can DIY it. I've been running mine for 5 years, DXing to Europe a fair amount on 10 meters, without radials, so it will work. Opinions are all over the place on this one, but I will say that with radials you'll KNOW what the boundary condition is at the bottom of the antenna, and it will be a good consistent boundary condition without RF leaking back down the coax. OTOH, $$$, visual impact, and probably OK performance without. Your call.
That LNR wire antenna is almost completely equal to an A99 without radials -- end-fed half-wave, etc., so it'll DX about the same if all else is about the same. If you go this way, hang it from a horizontal limb as far from the tree's trunk as practical. Anything over 5' should get it, but more will be better. You don't want to just slap it up against the trunk, that'll probably do weird things to the SWR and radiation pattern.