Home Alarm System - New House - Advice Please

After some advice. Grew up without an alarm system until parents recent new house had one installed. Great peace of mind now - would love to install in my own place (new build).

Am a complete newbie. Just wanted some advice on what to get - e.g. type of sensors, modules, types of alarms brand wise or features, other devices or add ons a newbie wouldn't know, what brands and systems are generally trusted and reliable. How to futureproof or provide flexibility with some smart choices/add ons now. Wire or unwired?

Think my parents alarm system is a Hills. Circa $800-1000 or so from memory. So looking to start there. Uses landline to inform nominated number of a set off. I am abit confused with my new house being NBN FTTH (so NBN box inside my garage and PCD on outside brick wall) and what options there are for system to notify you of intrusions? Do you use VoIP? NBN internet itself or even just install a GSM signal/device?

I have only contacted one company who offered/tossing up between Bosch and a hills system which supposedly links and works into the smartalarm.com platform. I'm yet to receive a detailed write up on what modules, detectors, alarm monitoring or other things it includes - but the reviews don't seem as great as what he was explaining. My worry is these online platforms will tie you into regular costs than once off setup of a permanent structure that can inform you of intrusions.

I just wanted a hardy, trusted system. Good sensors (what types do i consider), tamper resistant or at least able to notify you if they are - e.g. electricity cutting off, NBN/internet down, sensor wire cut or the alarm box/siren on the outside being knocked off and so forth. Smart home connectivity is fine but i don't want to get stuck with an ongoing commitment to a platform that's necessary to get your notifications of a break in (which I believe smarthome.com does? Your GSM phone contacts them, who contact you with a notification, rather than going directly to me).

I'd like the ability to add on or change things once alarms installed? Say GSM is activated now, if one can then connect it if a VoIp phone line is established? or perhaps add sensors or other devices and things to it? Perhaps 2 panels? One for master, one for a front entrance? Although both are close proximity.

Big noise, flashing lights outside (and more noise), partial and full features as far as sensors (to suit when your at home and wanting protection). Sensors that will work fine with furniture, our reverse cycle (as don't they pick up heat signatures?) and so forth. Added ability to tune into say one live camera to see if something is happening (if alarm goes off) would be great - but I assume you need a whole new system/device to record data and store it? And price would exponentially rocket?

We also wanted to keep in mind flexibility if we ever move out, sell the house etc in a few years. Is this easily portable to the next owner, renter, older generation etc.

I am Gen Y but am abit hesitant of being tied to this smarthome platform suggested - somehow I imagine these are more to suck you in for month to month fees , and complicating things? As opposed to more once off cost setups? I was told the system works still if you disconnect form the smart platform but somehow I don't feel in my gut that a platform subscription base would be in ones best interest?

Please help - newbie alert! Recommendations, rough pricing to expect? What options do i have?

P.S. Can I go ahead and order/activate NBN - the security guy suggesting alarm.com mentioned it was more complicating mentioning it to your service provider and them activating the two phone ports on your nbn equipment, and that they wouldn't really use that anyway in their systems. Is this true? Didn't want to order and setup NBN and find out I made things more difficult.