Hi & welcome to IIS

I'm a fellow Clayfield dweller myself- I used to live there ... aaaargh, my old stomping grounds.
Do the drive and head out to Sirius Optics and take a look at those scopes- nothing beats walking into the shop and eyeballing them for yourself. You may also be surprised at just how big those dobs are (as Malcom pointed out with the 12").
I bought my 10" dob from them and the price was reasonable and they even showed me how to collimate it. I've put wheels under the base and it's relatively easy to lug around. I like that the Saxon's & the Skywatchers have got the long tension handles (as opposed to GSO) as that's what I use to pull it along on wheels.

There's no way known I can handle a 12"

, I've maxed myself out with my a 10"

.
Perhaps also give some consideration to a 12" collapsible? With a go-to, it should still fall into your budget

.
Many people find the 10" just manageable and transportable for a sedan and it will give you serious views of the sky.
Do the drive .......... vrrrrrooooooooooooom!