Toilet question for plumbers

The flushing mechanism in one of our Gala brand toilets is constantly needing fixing leading to kids not flushing and at the moment we have a blockage in it somewhere so that water bubbles up in another toilet when the washing machine is emptying and the offending toilet is draining slowly. This has happened before and a plumber came to fix commenting on the narrow bend of the toilet and that all our pipes are under our concrete block house should a blockage occur there. Should I go choose a whole new toilet myself once I know p or s bend or rely on a plumber to Source me one. I am assuming I may as well replace the whole darned thing since its prone to blocking and the gala is a stupid design in my opinion having also lost two flusher knobs down two toilets. Any suggestions as to a brand?

Go to Bunnings.
Buy the Carmoa set for $139.
As for under the house, well you stuck with that.

Can't fault the 3 cheapie "Vienna" toilet kits I bought from mitre 10 and installed 3 weeks ago. very robust and easy to install. $140 each. (all s traps - I hate p traps - but you may be stuck with having to use whatever trap your current toilet is).

I think it's. S trap into the floor? May need to measure distance to wall or something. Well that's definitely better than the $400 plus ones I just googled. Mind you, the parts in the cistern may be useless in a few years but if they last 5 years I guess that's good if they are easy to replace. I might need the plumber anyway if my blockage doesn't budge. My husband is not keen on any DIY and I can see him blowing a fuse if I attempt it! No harm in going and looking though.

You definitely have a blockage in 1 of the common pipes either under the floor or outside somewhere. The bubbling noise caused by the other toilet and washingmachine is how I know.

Get someone round to unblock the drains. And while they are there ask them about replacing the toilet.