Hello!
Well, when we brought our Harry home he was a 'bigger boy' (quite huge actually!!!
) and we decided to only outdoor train him as he's a 'leg-lifter', too.
So we took him outside after all the trigger-times (on waking, after eating, after drinking, when he started to 'circle' etc.) or every hour or so during the day if none of that was happening!
While he was actually going we would say "GOOD wee-wee" or "GOOD poo-poo" and then throw a little party after he'd done a victory circuit of our back garden.....
. Harry got the hang of it soooo quickly, and was totally clean within 2 weeks....
It'll help that you're a stay at home mummy - and I wish you the very, very best of luck with your new little boy