The appropriate security system depends upon your house, neighborhood, proximity of your neighbors, and whether or not you have pets running around the house.
The system doesn't have to be terribly expensive, but should be well planned. Remember, the more secure the domain is against burglarly the more hazzardous it may be in case of fire and escape.
Since you are prepared to spend a lot of money, it is well worth the expense to have a monitored system. It can save you a lot of grief and may even save your life.
How much security do you want? Are you afraid of HOME INVASION or just have some concerns about burglary?
Hard switches are better than motion detectors. Wire closet doors. If you don't have pets running around, use floor mat switches under your carpeting.
The main trigger WHEN not at home would fire lights and dial the security company AND not an alarm that will irritate neighbors. Besides having several interior lights go on, have a beacon on top of your chimney. It will scare a burglar nothing flat. The light will create more of a scene than an alarm. It can also be seen further and immediately identifies the house. With an alarm, people get numb plus police (or whatever) have to hunt around to see where the noise is originating.
If you are at home, THEN I would also have it fire an alarm! Let your neighbors know if the alarm goes off, you are home and there is either a medical emergency or a home invasion!
Put up rose bushes outside your first floor windows.