They install right on a regular toilet. The ones that heat the water need an electrical outlet nearby - mine is currently on a heavy duty extension cord (not recommended).

Hi Wendy! I first tried the Joy Bidet, Model HC-3 from Amazon- it was around $65 I think and it was a great help. It had both hot and cold water by using the hot water hookups under the sink. When we moved we couldn't access the hot water hookup here so I upgraded to a coco bidet (which I am also using with an extension cord!) and really like it as well. But for a nice basic model, I thought the Joy Bidet was great. I'd say install it in the bathroom that is easiest for you to use as often as you need.

I have a TOTO Washlet and have had it for over 10 years. It replaced the toilet seat and lid. I'm not handy and so I had my plumber install it. It uses the hot/cold water source and does plug in to an outlet nearby. I have it installed in my bathroom rather than the main bathroom of my house. Selfishly, I don't want anyone else using this toilet. I couldn't live without it!

BioBidet I-3000. Under $200. Has the "enema" function which I love. No electrical outlet required. Can hook just up to the water valve on toilet or also to the hot water valve under the sink if you want hot. Easy to install. LOVE IT!