My gear, a Level IIIA full-coverage vest with Level IV rifle plates, weighs in at about 60 pounds, but that includesthe helmet and all of the other crap hanging off of it, like six carbine magazines, 5 pistol magazines, a couple of bangs and smokes, handcuffs, radio, gas mask, and various other little gadgets and required items. We have experimented with ballistic face shields but there is no real way to get good sight acquistion with those, even when using reflex optics. Eye protection is mandatory but usually takes the form of the almost disposably cheap Uvex ballistic safety glasses.
Our new vests are a little lighter and include upper arm protection. All of this stuff put together does make you move a bit slower, and can wear you out pretty quickly, which is why aerobic exercise and endurance is such a big requirement for us. We also train in all of this stuff very frequently, as that is about the only way to get used to it. Another downside is less flexibility and ability to move. This stuff only works well in teams where you have someone else to help you get into or over things. The plus side to all of this crap is that you do get a fair amount of inertia from it: if someone decides to resist, while we have some modified defensive tactics stuff for going hands-on, the simplest way is simply to linebacker them and knock their a** down, and the extra mass makes that fairly simple.
As far as armoring up the legs and arms goes, we have some Level IIIA leg protection, but they are rarely used. Arms are just kind of hanging out there; I guess that is why God gave us two, and we are required to shoot with either hand at various stages during qualififcation. I don't think we'll see much more in new armor developments or increased coverage until the material sciences catch up, which they seem to be doing rapidly.
As to legality, in most places, there is no restriction on non-LE purchase of body armor, although it is unlawful for felons to posess it in my state. There is a federal staute that prohibits wearing armor during the commission of a felony, but that is something that is basically an additional charge and not likely to come up too often.
As to full coverage armor, there are some options available out there, though I am not aware of anyone using such a set-up for entry work. US Cavalry was selling a set-up like this, that included full leg and arm protection with an Interceptor vest as the base system, but I can't find any pictures on their website right now. I think the whole thing ran about $4K and looked pretty darned buly.