Most are glued down with a special type of epoxy rather than mechanically fastened but the hardest part will be finding something that matches the decor of the house.

Also, don't forget about the what the right decor will do.

It needs to be sufficient to heat the space if you want it for something other then decoration. 

I want them to be able to buy a new shower curtain or other decorations to make it "homey" for them.I don't believe you can require that they are a non-smoker.

Follow some home decorator blogs(I personally like Jones Design Company, The Inspired Room, Decor8 just to name a few) those have the most information and you are getting in touch with what the market wants.Here is my REI board on pinterest.https://www.pinterest.com/nikkib123/rei-rehab-idea...Popular neutral paint colors are "Graiges" they are gray based colors.

floors in the living room are great, all the other walls are fine.that's about all that I would do, of course I would decorate it, but I can guesstimate that myself.if someone could give a ballpark that would be awesome.

In our lower end 2BR/1BA multifamily units we use mini-blinds and provide a decorative curtain rod in the living room and basic double rods in the bedrooms, for tenants to hang their own curtains.

If its an older hvac unit outside you may build a decorative lattice guard around it to hide it, paint it too.

We also like to dream and decorate. 

The apartment units are identical, while the cottages vary in color, interior décor, etc....